The extension of the oil and gas windfall tax gives the SNP much-needed ammunition in its bid to win Tory seats in north-east Scotland, where 100,000 workers depend on the hydrocarbon industry.

Chancellor Jeremy Hunt has promised to expand taxes on fossil fuel profits, which could damage the fortunes of the Conservative Party in northeast Scotland, where many fear the transition to green energy will lead to job losses.

“The Conservatives are shooting themselves in the foot with the windfall profits tax,” said one SNP source. “It's unclear whether they are champions of the oil and gas industry.”

Despite opposition from the Scottish Conservatives, Hunt announced in Wednesday's budget a 12-month extension to the energy profits tax levied on oil and gas companies.

Soon after, the chancellor admitted that Scottish oil and gas had failed, with nationalists describing it as an attack on Scotland's resources ahead of a general election expected this year.

The comments, made in an interview with the BBC on Thursday, drew the ire of Westminster SNP leader Stephen Flynn, who wrested the Aberdeen South seat from the Conservatives in 2019.

“Westminster has once again betrayed north-east Scotland to fill a vacancy in the UK Treasury,” Flynn said in a statement.

The Scottish Conservatives have recently positioned themselves as friends of the fossil fuel industry, as opponents in the SNP and Labor parties have opposed new production licenses in mature North Sea oil fields. Labor has also pledged to extend a windfall tax on oil and gas profits if it wins the election.

Furious Scottish Conservative leader Douglas Ross promised not to vote on the bill. But Scotland Secretary Alister Jack did not object to the extension, saying it was a “difficult decision” that would require huge energy profits to be returned to support better public services.

The Scottish Conservatives hold three seats in the north-east and are aiming to win two more seats in the region. The party expects the SNP battleground with the Conservatives to focus on the Scottish Government's lack of public service delivery rather than the Conservatives' performance in Westminster.

SNP strategists said the move could reignite historic nationalist resentment over the £400 billion in North Sea revenues that have largely funded Conservative policies opposed by most Scots over the past 50 years, especially in the 2000s. The oil boom of the Margaret Thatcher era in the 1980s.

A former SNP MP has warned that the nationalist party is “riding on two horses” as the main battle is with Labor in Scotland's midlands, where voters care more about net zero than oil.

“There's not a lot of sympathy for energy companies that make crazy profits during good times. That's just the reality,” they added.

Indeed, the Scottish Conservatives reject the idea that the SNP or Labor can be trusted on oil and gas issues.

The SNP opposes extending the windfall tax but also calls for a halt to future production in the North Sea. Shadow net zero, energy and transport minister Douglas Lumsden, MSP, described the position as “ridiculous”.

He added: “This ridiculous claim – coming from a party that boasts of ending Aberdeen’s status as the oil and gas capital of Europe – is an insult to people’s intelligence.”

Last year, Scotland's First Minister Humza Youssef said the country would develop from Europe's oil and gas capital to a net-zero capital.

The SNP and Green Scottish Government coalition are seeking to boost their climate credentials by funding supply chains for the renewables industry and launching consultations on an energy strategy to “presume” new oil production in the North Sea.

SNP officials pointed to data from regulator the North Sea Transition Authority showing gas production in the northeast is expected to fall by 95% by 2050, even with new licenses.

They argue that while the granting of licenses is out of the SNP's hands, a decline in oil and gas remains inevitable.

The Scottish Greens have called for a reversal of the “perverse mechanism” in the windfall profits tax, which gives oil and gas producers a tax break of 91p for every £1 they invest in their UK operations, rather than spending it on renewable energy.

The complex equation of reducing fossil fuels while increasing renewable energy is causing concern across the Northeast.

Climate campaigners are pushing for a rapid shutdown of hydrocarbons to help meet Scotland's ambitious 2045 net-zero emissions target. Oil and gas advocates, meanwhile, argue that maintaining domestic production can provide energy independence while financing the transition.

“Frankly, none of the three major parties have appeared particularly committed on energy policy over the past two years,” said Fergus Mutch, managing partner at consultancy True North, adding that the windfall tax mark “The fourth tax raid on the North Sea in just two years”.

He said voters in the northeast, with many rural areas previously held by the Lib Dems, were likely to split in different directions.

He said: “If a party is willing to say: 'Maximize domestic production while we still need oil and gas, maintain jobs that are dependent on oil and gas and target the revenue generated in the oil and gas sector, then there is A really ripe constituency to choose from. Transition'.”