Rishi Sunak has been accused of having “thrown in the towel” on global efforts to tackle the climate crisis with the Prime Minister poised to water down the UK’s net zero targets.

With an eye on a general election expected next year, the Prime Minister risks triggering a bitter Tory row with the move, which has dismayed the environmental wing of his party but delighted those who fear the price of going green will cost votes.

He has already been heavily criticised for announcing new oil and gas licenses in the North Sea.

The Prime Minister is expected to water down key climate targets in a speech later today.

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Home Secretary Suella Braverman, a key figure on the Conservative right, backed the Prime Minister for making “difficult decisions” on net zero and putting “household costs first”.

“We’re not going to save the planet by bankrupting the British people,” she told Times Radio.

Mr Sunak has said he will set out a “proportionate” approach to cutting emissions but will maintain the overall commitment to reaching net zero by 2050.

Scotland has committed to becoming net zero by 2045.

Measures being considered include weakening the plan to phase out gas boilers in England from 2035 and delaying the ban on the sale of new petrol and diesel cars south of the Border – currently due in 2030 – by five years, the BBC reported.

The policies are largely devolved to the Scottish Government, but SNP and Green ministers could miss out on funding for their ambitious net zero strategy – while some measures and investments are crucial on a UK-level.

There is also speculation that recycling schemes could be under threat of being binned – raising questions over the Scottish Government’s deposit return scheme, which is now set to be delivered in tandem with the UK Government.

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The BBC suggested that new taxes to discourage flying will be ruled out, alongside any plans to encourage diet changes and carpooling.

In a letter to the Prime Minister, SNP Westminster leader, Stephen Flynn, has warned there is a “global race to a net-zero future”, adding “you’ve just thrown in the towel”.

He said: “Your clear intention to renege on the promises made to citizens and businesses on achieving green growth and green jobs, puts at risk both our climate obligations and our economic future.

“Your predecessors in office were very successful in making a mess of the present - you seem intent on making a mess of all our futures.”

Mr Flynn labelled the U-turn as a “disgraceful decision will hit hardest in Scotland”.

He said: “We have the energy, the people and the ambition to compete in that global race to net zero – an ambition which will help deliver economic growth, cut energy bills, cut emissions and create jobs.

“All the evidence tells us that we can protect and create jobs in Scotland by ensuring that we get the energy transition right, but your Westminster government now doesn’t even seem to want to have a transition, just a cliff edge.

“The clearest outcome from your intention to drop out of the global race to net-zero is that both the US and the EU will easily beat the UK in this green gold rush.

“They will secure the jobs, the technology, the energy security, and the economic growth that will flow from quickly transitioning to green energy. Backwards Britain will be left behind.”

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Jamie Livingstone, head of Oxfam Scotland, said: “It beggars belief that the Prime Minister seems intent on rowing back on key climate commitments, just at the point when we should be speeding up, not slowing down climate action.    

“In stark climate contrast, the First Minister has this week rightly talked about the need for greater urgency and action. However, history will judge our leaders by what they do, not what they say, and neither the Scottish or UK Government is investing at the scale and speed needed to slash emissions.”

He added: “Oxfam’s research shows that common sense taxes on the UK’s biggest and richest polluters last year alone could have raised up to £23 billion, whilst protecting ordinary people’s pockets. The money is there, the ideas are there; what’s missing is the political courage to bring them together to deliver fast and fair climate action.  

“The climate crisis cannot be wished away; the choices our leaders make today will directly impact on the number of lives the climate emergency claims. It’s that simple.”

STUC general secretary, Roz Foyer, warned the decision would impact workers.

She said: “This is an incredibly desperate move from an increasingly desperate Prime Minister seeking whatever polling advantage he can muster at the expense of thousands of lives around the world impacted by climate change.

“Slowing climate action risks being a disaster for workers in Scotland and endangers thousands of manufacturing jobs that need futureproofing now.

“It puts us at a further competitive disadvantage in developing the industries of the future, and, ultimately will lead to higher energy bills and more fuel poverty.

“While the STUC has always been clear that there are practical difficulties to delivering net zero, these will only be overcome by investing in the industries of the future. This includes taking back control of our energy and transport systems and delivering a national retrofitting programme.

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“If Rishi Sunak won’t deliver the investment needed then he should at least devolve greater borrowing powers to the Scottish Parliament to enable them to do so.”

Mr Sunak, who is attempting to draw a dividing line with Labour before the next general election, sought to position himself as the bringer of “real change” who will “put the long-term interests of our country before the short-term political needs of the moment”.

The prospect of a major shift in the Conservatives’ approach was swiftly condemned by the green wing of the party.

Former COP26 president Sir Alok Sharma warned that watering down the commitments could cost the Tories votes.

He told BBC Radio 4’s Today programme: “I think it’d be incredibly damaging for business confidence, for inward investment, if the political consensus that we have forged in our country on the environment and climate action is fractured.

“And, frankly, I really do not believe that it’s going to help any political party electorally which chooses to go down this path.”

Sir Alok said delays on policies such as banning new petrol and diesel cars could mean tougher curbs in other areas.

Chris Skidmore, a Conservative former energy minister who led a government-commissioned review on net zero, said: “Rishi Sunak still has time to think again and not make the greatest mistake of his premiership, condemning the UK to missing out on what can be the opportunity of the decade to deliver growth, jobs and future prosperity.”

Shadow energy secretary Ed Miliband said: “This is a complete farce from a Tory Government that literally does not know what they are doing day to day.”

The potential policy shift also alarmed the car industry, which has invested on the basis of a 2030 shift away from petrol and diesel.

Ford UK chairwoman Lisa Brankin said: “Our business needs three things from the UK Government: ambition, commitment and consistency.

“A relaxation of 2030 would undermine all three.”