Business

The government has announced a £100million package of measures aimed at unlocking private investment for Britain’s entrepreneurs, start-ups and scale-ups, but business leaders have rounded on the plans, warning that established small firms are being forgotten while the broader strategy for enterprise remains “in a muddle.”

Brought into force at the start of the new tax year, the changes expand eligibility for the Enterprise Management Incentives scheme, which allows qualifying companies to offer employees tax-advantaged share options. The package also doubles the amount a company can raise through the Enterprise Investment Scheme and Venture Capital Trusts, both of which offer tax reliefs designed to channel capital towards higher-risk, early-stage businesses that struggle to secure growth funding.

Rachel Reeves, the Chancellor, said she was “backing business with a more active state” and making “big commitments to industry,” adding that the measures would help wealth creators access the finance critical to their success.

The reception from the business community, however, was notably cool. Critics pointed to the stark contrast between the sums involved and the £25billion a year the Treasury is now raising from employers following its increase to National Insurance contributions.

Katrina Young, a digital transformation strategist at KYC Digital, said the arithmetic does not flatter the policy. The expanded EIS, VCT and EMI reliefs are targeted at companies with gross assets of up to £120million and as many as 500 employees, she noted, leaving out the dental practices, family logistics firms and small bakery chains that employ the bulk of the workforce yet face an additional £900 per employee per year since the NI threshold was cut from £9,100 to £5,000. She pointed to British Chambers of Commerce data showing that 82 per cent of firms expect the NI rise to affect their business, with 58 per cent anticipating reduced recruitment.

The hospitality sector offered a particularly blunt assessment. Jess Magill, co-founder of Devon-based Powderkeg Brewery, said there is little point in throwing money at getting new companies off the ground if they are then taxed out of existence. She argued that what is needed is support for established businesses to survive, warning that popular venues are closing every week and the domino effect on suppliers is worsening.

Colette Mason, an author and AI consultant at London-based Clever Clogs AI, echoed those concerns, describing the £100million as “miserly” when set against the NI rises. She noted that the EMI expansion targets roughly 1,800 scale-up companies over five years, firms already attractive to investors, while the businesses that employ most people are cutting hours, freezing wages and reconsidering whether to hire at all.

Samuel Mather-Holgate, managing director of Swindon-based Mather and Murray Financial, said the government is sending mixed signals at precisely the wrong moment, increasing the amount companies can raise while simultaneously slashing the benefits for investors in those same businesses. The UK, he argued, needs to be incentivising companies both to start and to stay on British soil.

The announcement is likely to intensify the debate over whether the government’s growth agenda is reaching the businesses that need it most, or merely recycling a fraction of what it has already taken.

Read more:
Government’s £100m pledge for innovators dismissed as a drop in the ocean after £25bn National Insurance raid

Kate Alessi, Google’s managing director for the UK and Ireland, has pushed back firmly against warnings that artificial intelligence will trigger widespread unemployment, insisting that the greater risk lies in failing to equip workers with the skills to thrive alongside the technology.

Speaking as Google unveiled a new national upskilling programme backed by £2 million in grant funding from Google.org, Alessi argued that history offered a reassuring precedent. Every previous wave of technological disruption, she noted, had prompted the same anxieties about disappearing jobs – and every time, the fears had proved overblown as new roles emerged to replace the old.

Her intervention comes at a pointed moment. In January, the Mayor of London, Sadiq Khan, cautioned that AI could bring about a new era of mass unemployment without proper oversight, while Bank of England governor Andrew Bailey drew comparisons with the Industrial Revolution, stressing the need for retraining and education on a significant scale.

Alessi does not deny that change is coming, but she frames it rather differently. Citing research from the policy consultancy Public First, she pointed out that roughly six in ten UK jobs are expected to be enhanced rather than eliminated by AI. The challenge, she maintained, is ensuring that people are prepared to step into the roles the technology creates, not simply bracing for the ones it displaces.

The figures suggest there is considerable ground to make up. According to new research commissioned by Google, although nearly two thirds of the UK population have tried AI tools, just one in ten consider themselves advanced users. Only a quarter felt they were deploying AI in ways that saved them meaningful time or gave them genuinely new capabilities.

“Most people are really only scratching the surface,” Alessi said.

To address that gap, Google is rolling out a series of practical initiatives. Alongside the grant funding, the company plans to run Gemini tours across universities, aimed at ensuring graduates enter the workplace with a working knowledge of AI. It will also stage a series of pop-up events branded as “squeeze the juice” bars in towns and cities around the country, designed to show ordinary users how to move beyond basic prompting to tackle more complex tasks – from automating routine admin to conducting in-depth research.

Read more:
Don’t fear AI job losses – invest in training, urges Google’s UK boss

Increased defence investment stands to deliver a significant windfall for the British economy, with new analysis suggesting that the government’s ambitious spending commitments could add £30 billion a year to national output within two decades.

Research by EY, the professional services giant, has found that raising defence expenditure from its current level of 2.5 per cent of GDP to between 3.5 per cent and 5 per cent by 2035 would produce what the firm describes as “significant long-term benefits” for growth and productivity.

The findings lend economic weight to what has until now been framed largely as a security imperative. Sir Keir Starmer pledged at the Nato summit in June 2025 to spend 5 per cent of GDP on national security by 2035, including 3.5 per cent on core defence, as geopolitical tensions and pressure from Washington compelled allies to bolster their military budgets.

Yet translating ambition into action has proved problematic. The government’s ten-year defence investment plan, expected last autumn following the publication of its strategic defence review, has been repeatedly delayed owing to a £28 billion funding gap in the Ministry of Defence budget over the next four years. Neither the Treasury nor the MoD has set out a clear pathway to meeting the spending targets.

EY’s analysis, drawing on Office for Budget Responsibility forecasts and GDP projections, estimates that reaching the 3.5 per cent target would require an additional £31 billion of real-terms spending by 2035. Hitting 5 per cent would demand an extra £77 billion.

The potential returns, however, are considerable. The proposed increases could lift GDP by 0.8 per cent, generating £30 billion in additional annual economic output by 2045, according to the firm’s modelling.

Central to EY’s thesis is the relatively self-contained nature of Britain’s defence industry. Approximately two thirds of annual private sector spending by the MoD flows to UK-based suppliers, with just 31 per cent going overseas either directly or through the supply chains of domestic companies. That high proportion of domestic retention means more of every pound spent stays within the British economy, supporting jobs and underpinning industrial capacity.

Peter Arnold, UK chief economist at EY, said the defence sector is more capital-intensive than other areas of government spending, particularly in its support of manufacturing. A considerable share of the MoD’s budget is also directed towards research and development, which has the potential to produce dual-use technologies with commercial applications in fields such as aviation and cybersecurity.

Nearly a third of the MoD’s budget, roughly £20 billion, is allocated to capital expenditure on infrastructure, equipment and technology, rather than routine operational costs such as salaries and accommodation. That balance between current and capital spending gives defence investment an outsized economic multiplier compared with many other areas of public expenditure.

EY’s report also urged ministers to accelerate procurement processes and provide greater clarity over equipment priorities to encourage private sector investment. The call echoes longstanding frustrations among smaller defence contractors. The Federation of Small Businesses has argued that the procurement system remains skewed towards larger firms, leaving smaller enterprises struggling to compete for contracts.

The MoD said it was delivering what it described as the biggest uplift in defence spending since the Cold War, with £270 billion of investment across the current parliament. Since last July, the department said it had signed almost 1,200 major contracts, with 93 per cent of that spend directed to UK-based companies. It also pointed to the launch of a dedicated Defence Office for Small Business Growth earlier this year and a commitment to increase spending with SMEs by £2.5 billion a year by May 2028.

Whether these measures will prove sufficient to close the gap between political rhetoric and fiscal reality remains to be seen. But EY’s analysis makes a compelling case that, if managed wisely, increased defence spending need not be viewed solely as a cost of security. it could become a genuine engine of economic growth.

Read more:
Higher defence spending could unlock £30bn annual boost for UK economy

The price of oil climbed above $111 a barrel on Tuesday as mounting anxiety over stalled diplomatic efforts in the Gulf pushed energy markets higher and left equities treading water.

Brent crude gained 1.6 per cent to $111.57 in early Asian trading, extending a rally that has seen the benchmark surge more than 50 per cent since Iran’s effective blockade of the Strait of Hormuz, the chokepoint through which roughly a fifth of the world’s oil and liquefied natural gas once flowed freely.

The immediate catalyst was Tehran’s rejection of a US peace proposal on Monday. Iran instead issued its own ten-point counter-plan, relayed through Pakistan, according to state media. Washington’s deadline for agreement expires at 1am UK time on Wednesday, and President Trump has made no secret of the consequences, warning that failure to reach a deal would see Iranian infrastructure reduced to rubble.

For businesses already grappling with elevated input costs, the prospect of a further escalation is deeply unwelcome. The International Energy Agency has described the strait’s closure as the most severe supply disruption in the history of the global oil market, with Brent futures touching nearly $120 a barrel last month when regional energy assets came under attack.

Some commodity analysts have gone further still, warning that a prolonged conflict could drive prices as high as $200 a barrel, a scenario that would dwarf the energy shocks of the 1970s and inflict serious damage on margins across transport, manufacturing and retail.

Stock markets reflected the uncertainty. The FTSE 100, reopening after the Easter break, was effectively flat at 10,425, whilst bourses in Frankfurt and Paris managed only modest gains. In Tokyo, the Nikkei closed barely changed.

Vasu Menon, managing director of investment strategy at OCBC in Singapore, captured the prevailing mood, noting that any US strikes on Iranian power infrastructure would represent a marked escalation, raising the spectre of retaliatory action against Gulf energy facilities.

For UK firms with exposure to global supply chains, the next 24 hours could prove decisive. A deal would offer some relief to energy markets; a breakdown in talks would almost certainly send oil prices sharply higher and deepen the squeeze on an already stretched global economy.

Read more:
Oil price surges past $111 as Strait of Hormuz deadline looms

Britain’s manufacturing sector is staring down the barrel of a near-£1 billion increase in annual business rates, piling further pressure on an industry already reeling from surging energy bills and escalating employment costs.

Analysis by Make UK, the manufacturers’ organisation, of official data on rateable value changes between 2023 and 2026 estimates that the sector will shoulder an additional £939 million a year in business rates from this month. The figures lay bare a stark imbalance: while manufacturing accounts for roughly 10 per cent of the economy, it contributes more than a fifth of all business rates revenues.

A companion survey by Make UK paints a bleak picture across the shopfloor. Nearly nine in ten manufacturers reported an increase in their rates for April, with two thirds seeing rises of up to 20 per cent. More troublingly, almost one in five companies face increases of between 20 and 50 per cent, and a small but significant minority, three per cent, have seen their rateable values climb by as much as 100 per cent.

The timing could scarcely be worse. The rates increase arrives in the same month that around half of manufacturers will renegotiate their energy contracts, compounding the impact of higher national insurance contributions and other employment-related burdens that came into force at the start of the tax year.

Verity Davidge, policy director at Make UK, described the current system as outdated and called the increase a hammer blow to one of the government’s priority sectors. For many companies, she warned, survival itself has become the benchmark of success.

The survey reveals just how heavily business rates weigh on the sector’s finances. Nearly a quarter of manufacturers rank them as their second-largest cost, while one in ten say rates represent their single biggest expense. Make UK’s modelling suggests the squeeze could put approximately 25,000 jobs at risk as firms consider reducing headcount to absorb the hit.

At the heart of manufacturers’ frustration is a rating system based on square footage rather than business performance. Under the current model, a small or medium-sized enterprise occupying a large factory floor can be classified as a high-value property despite modest turnover and a modest workforce. This structural quirk means that more than half of the sector’s rateable values exceed £100,000, and one in five manufacturers occupies a facility valued at more than £500,000, pushing them into a new high-value multiplier bracket that effectively penalises past investment.

The system also creates a perverse disincentive for manufacturers seeking to go green. Installing renewable energy infrastructure increases a facility’s value and, with it, its rates bill, an unwelcome contradiction at a time when government policy is urging industry to decarbonise.

At the other end of the scale, just six per cent of manufacturers hold a rateable value below £20,000, leaving the vast majority locked out of reliefs such as the small business rates relief scheme.

Make UK is now pressing the government to overhaul the system fundamentally. Among its proposals, the organisation is calling for alternative models that link rates to business size, type or turnover rather than physical footprint, ensuring that charges reflect who is occupying a property rather than simply how large it is. It also wants a 12-month notice period before new rates take effect following any revaluation, backed by a more generous transitional relief in the first year. Finally, it argues that local authorities should publish impact reports demonstrating how business rates revenue is being reinvested in local communities, a move designed to give firms a clearer sense of value for money.

For an industry navigating tariff uncertainty, global supply chain disruption and a domestic cost environment that grows more hostile by the quarter, the message from the manufacturing lobby is unambiguous: the current rates regime is broken, and without reform, the consequences will be measured in lost jobs, shelved investment and diminished competitiveness.

Read more:
Manufacturers bracing for £1 billion business rates bombshell as April cost crisis deepens

Bristol is about to join the big league of British live entertainment, with the city’s forthcoming Aviva Arena setting its sights on staging the Brit Awards within its first years of operation.

The 20,000-capacity indoor venue, which is taking shape on the historic Filton Airfield in north Bristol, the very site where every British-built Concorde rolled off the production line, is on track to open in late 2028. Its backers believe it will plug a glaring gap in the country’s events infrastructure, given that the south-west remains the only English region without a major arena.

The project sits at the heart of a broader development called YTL Live, which will occupy the three vast Brabazon Hangars once used to assemble supersonic aircraft. The central and largest hangar will house the arena itself, flanked by conference and exhibition spaces designed to keep the complex busy well beyond gig nights. Organisers expect the venue to stage upwards of 120 major events each year, generating an estimated £1 billion for the wider Bristol economy over its first decade.

Andrew Billingham, chief executive of the Aviva Arena, said the ambition extends well beyond regional pride. The venue wants a place on the global touring circuit, and the Brit Awards sit firmly in its crosshairs following the ceremony’s well-received stint in Manchester earlier this year.

The arena’s specification suggests those ambitions are not merely fanciful. Plans include 20 state-of-the-art dressing rooms, extensive production facilities and what is billed as Europe’s largest services yard, with capacity for up to 60 touring lorries at once. A new railway station, Bristol Brabazon, is due to open this autumn, giving the site a direct public transport link that many rival venues lack.

Behind the project is YTL, a Malaysian infrastructure conglomerate and the largest Malaysian investor in the United Kingdom, whose British portfolio already includes Wessex Water. The group acquired the Filton site roughly a decade ago with a vision that went far beyond housebuilding, it set about creating an entire mixed-use community encompassing homes, workplaces and leisure. Construction of the arena is expected to support more than 2,000 jobs, with a further 500 permanent roles once the doors open.

For Bristol, a city whose creative economy already punches well above its weight, the arrival of a venue of this scale represents a significant commercial moment. If Billingham and his team can deliver on the Brit Awards pledge, it would mark the latest step in the ceremony’s journey away from its traditional London base, and confirm that the south-west finally has a stage to match its cultural ambition.

Read more:
Bristol’s new arena sets sights on hosting the Brit Awards

GB News has made a bold bid for access to the public purse, arguing that government broadcasting grants should be opened up to competitive tender rather than flowing automatically to the BBC.

The loss-making news channel, backed by hedge fund financier Sir Paul Marshall, set out its case in a submission to the government’s consultation on the BBC’s royal charter. At its heart is a call for “contestable funding”, a mechanism that would allow broadcasters beyond the traditional public service operators to bid for taxpayer-backed support.

The BBC’s World Service is the most obvious target. Once funded entirely by Whitehall, the service now draws primarily on the licence fee but still receives grants from the Foreign, Commonwealth & Development Office worth £137 million last year. GB News believes it should be eligible to compete for a share of that pot, assessed on criteria including quality, audience reach and value for money.

It is a striking proposition from an organisation that has accumulated losses exceeding £100 million since launching in 2021, and one that is unlikely to find a warm reception at Broadcasting House. GB News framed the argument in the language of market competition, contending that opening funding to tender would drive innovation and encourage what it called “diversity of thought and content”.

The channel pointed to precedent. Between 2019 and 2022, two pilot schemes, the Young Audiences Content Fund and the Audio Content Fund, distributed £48 million across a range of broadcasters and independent producers. GB News also drew attention to New Zealand’s NZ On Air model, which allocates public money to a variety of media outlets, suggesting a similar framework could bolster plurality in Britain’s broadcasting landscape.

The submission to the charter review is part of a broader lobbying campaign. In a separate filing with Ofcom, GB News made a parallel case for contestable funding. It is also pressing for prominence rights currently enjoyed only by the established public service broadcasters, the BBC, ITV, Channel 4, Channel 5 and S4C, which guarantee their channels favourable positioning on television sets, albeit in return for strict obligations around regional production and news output.

Whether the government has any appetite for redirecting public funds towards a commercially owned, politically divisive broadcaster remains to be seen. But GB News’s intervention ensures the question of who qualifies as a public service provider, and who should pay for it, will sit squarely at the centre of the charter debate.

Read more:
GB News makes its pitch for a slice of public broadcasting funds

The scale of the tax burden heaped on British businesses since the pandemic has been laid bare by new HMRC data showing that national insurance receipts have surged nearly 40 per cent in just six years.

Figures from HM Revenue & Customs reveal that national insurance contributions reached £198 billion in the year to February 2026, a sharp rise from the £143 billion collected over the equivalent period in 2019-20. The increase amounts to an additional £55 billion a year flowing into Treasury coffers, much of it drawn directly from employer payrolls.

The trajectory has steepened markedly over the past twelve months. Receipts climbed 15 per cent in a single year following changes introduced in April 2025, when the earnings threshold at which NICs apply was cut to £5,000 and the main employer rate was raised to 15 per cent. Together, the measures, announced by Rachel Reeves in her first budget in October 2024, represented a £25 billion annual tax increase targeted squarely at employers.

From this month, businesses face further cost pressures. The national minimum wage has risen by 4.1 per cent, compounding a 6.7 per cent increase the previous year. Business rates have also gone up for clubs and restaurants, though pubs were partially shielded from the rise in one of several policy reversals by Sir Keir Starmer’s government.

Robert Salter, a director at accountancy firm Blick Rothenberg, said the chancellor’s insistence that employer NIC rises do not constitute a tax on working people is at odds with mainstream economic thinking. He argued that higher employer social security costs tend to suppress employment, a pattern he said is already visible in rising joblessness over the past year, while feeding through indirectly into higher inflation for consumers.

The broader fiscal picture offers little prospect of relief. According to the Office for Budget Responsibility, the United Kingdom’s overall tax burden is set to reach a postwar high of 38.5 per cent of GDP by 2030-31. Income tax receipts have risen even more steeply than NICs, jumping 69 per cent to £328 billion since the onset of the pandemic.

Frozen tax thresholds, a policy of fiscal drag first introduced by Rishi Sunak in 2021 and since extended by Reeves to the end of the decade, have drawn millions more earners into higher tax brackets. Taken over its full duration, the freeze is on course to rank among the largest effective tax increases on individuals in modern British history.

Meanwhile, the conflict in the Middle East has sent oil and gas prices climbing, adding to input costs for manufacturers. Industry surveys published last week showed cost inflation in the manufacturing sector accelerating at its fastest pace since 1992.

For businesses already contending with higher wages, steeper NICs and elevated energy costs, the cumulative burden raises serious questions about the government’s ability to stimulate the private-sector growth it says is central to its economic strategy.

Read more:
Businesses shoulder a £200 billion National Insurance Bill as payroll tax receipts surge 40% since pandemic

Fresh incentives designed to turbocharge Britain’s start-up and scale-up economy have officially taken effect, with the government forecasting that the measures will channel an additional £100 million into high-growth companies across the country.

The changes, first announced by chancellor Rachel Reeves in last autumn’s budget, target three pillars of early-stage business finance: employee share schemes, the enterprise investment scheme (EIS) and venture capital trusts (VCTs). Together, they represent the most significant expansion of tax-advantaged support for young companies in recent years.

At the heart of the package is a dramatic widening of the enterprise management incentive (EMI) scheme, the mechanism that allows employees to acquire company shares at a predetermined price, potentially well below market value if the business performs strongly. Gains realised on the sale of those shares are subject to capital gains tax rather than income tax, making the arrangement considerably more attractive for employees willing to back a growing firm.

Under the new rules, the gross assets ceiling for companies qualifying for EMI has quadrupled to £120 million, while the maximum number of employees a participating firm may have has doubled to 500. The cap on the total value of unexercised options held across a company at any one time has likewise doubled, rising to £6 million. The Treasury estimates that roughly 1,800 of Britain’s fastest-scaling businesses will now be eligible, opening up share-based rewards for an estimated 70,000 workers.

Dom Hallas, executive director at the Startup Coalition, welcomed the changes, describing them as a genuine boost for the ecosystem and noting that the expanded headroom would help ambitious firms compete more effectively for the talent that ultimately determines whether a business can scale successfully.

Eva Barboni, who leads the Enterprise Britain movement, echoed the sentiment, arguing that widening access to share ownership would strengthen the ability of British scale-ups to attract and hold on to the people they need to compete on the world stage.

Alongside the EMI expansion, the government has doubled the lifetime company investment limits for EIS and VCTs, two schemes that offer investors more favourable tax treatment when they back early-stage ventures. The ceiling now stands at £24 million, with annual company investment limits rising to £10 million. A higher gross assets threshold of £30 million before share issue and £35 million afterwards means a broader pool of companies can tap into the incentives.

Read more:
Budget tax breaks worth £100m come into force for founders and start-ups

One of the Labour Party’s most prominent financial backers has called on Ed Miliband to slam the brakes on North Sea oil and gas exports, warning that the escalating conflict with Iran could leave Britain dangerously short of fuel.

Dale Vince, the green energy entrepreneur behind Ecotricity, said the Energy Secretary must be prepared to act decisively, instructing operators in the basin to keep hydrocarbons at home should supplies tighten further. Speaking to the Daily Telegraph, he argued it would be “bonkers” to continue shipping British barrels overseas while households and businesses brace for a squeeze.

“We can ban exports from the North Sea. China have done it,” Mr Vince said, pointing to Beijing’s willingness to prioritise domestic consumption during periods of strain. “If we are facing the prospect of a fuel shortage, then stop exporting it.”

Britain currently pumps around 53 million tonnes of crude annually, the bulk of which heads to refineries in the Netherlands, Poland and beyond. In a quirk of the global trading system, the country then imports roughly 51 million tonnes to feed its own forecourts and power stations, leaving it fully exposed to price spikes on world markets.

That exposure has become painfully evident since hostilities in the Gulf erupted last month. Roughly one-fifth of global oil and liquefied natural gas supplies remain bottled up behind Tehran’s closure of the Strait of Hormuz, sending Brent crude soaring to about $109 a barrel from $77 at the start of the month. Wholesale gas has jumped by around three-quarters, pushing up pump prices and prompting warnings from suppliers that household energy bills will climb sharply in the months ahead.

The crisis has reignited a fierce debate over Britain’s energy security, with industry voices pressing Mr Miliband to accelerate drilling and to rubber-stamp the contested Rosebank and Jackdaw fields. Reports on Friday suggested the Energy Secretary may approve Jackdaw while blocking Rosebank, a decision likely to inflame both sides of the argument.

Mr Vince remains opposed to any fresh expansion but believes the Government should extract maximum value from the ageing basin’s remaining reserves. He proposed offering existing operators contracts for difference, a mechanism more commonly associated with renewables, to prevent what he described as “a cliff-edge event where operators walk away because prices collapse”.

The intervention is certain to provoke fierce resistance from private producers, who rely on international buyers for the lion’s share of their revenue. Yet Mr Vince said the present moment exposes the folly of exposing Britain’s domestic output to volatile global benchmarks.

“We’ve opened ourselves up to global markets, but the concept of globalisation is costing us an arm and a leg when there’s an energy crisis,” he said. He contrasted the British approach with that of the United States, which restricts certain fuel exports and has long enjoyed the benefit of cheaper domestic gas. “We’re back to a situation where whatever we make in the North Sea costs us the global price.”

Mr Vince also used the moment to argue that the conflict should prompt a wider rethink of Britain’s dependence on Washington. The US has become the largest single supplier of crude to the UK, accounting for roughly 30 per cent of imports. “It alarms me to be reliant on the US for anything,” he said, describing the current American administration as “a very undependable regime” and calling for greater strategic independence from Washington.

Ultimately, he argued, the long-term answer lies in weaning the country off hydrocarbons altogether. “The answer is to get off fossil fuels and to break the link between the global price of fossil fuels and those that we make in our country.”

A Government spokesman defended the current approach, insisting Britain benefits from “a strong and diverse mix of fuel supply” spanning both imports and domestic production. Officials added that UK refinery output of petrol from crude exceeded demand in 2025, leaving a surplus available for export.

Read more:
Vince calls on Miliband to halt North Sea oil exports as Iran war rattles supply