Rishi Sunak has been accused of an "unforgivable" U-turn on efforts to tackle the climate crisis after rowing back on the UK Government’s key climate pledges.

The Prime Minister stressed the UK’s 2050 legal net zero target will remain intact, but he confirmed a raft of environmental policies for England and the UK will be watered down or abandoned.

The rethink means the proposed 2030 ban on new petrol and diesel cars has been pushed back to 2035.

Read more: Analysis: What message does Rishi Sunak's watered-down net zero strategy send?

Despite complaining about “short-term thinking” on net zero, the Prime Minister’s change of tune could mean more drastic action will be needed in future years to ensure the UK meets its 2050 legal aim.

Mr Sunak's decision to push forward the ban on new petrol and diesel cars has resulted in a backlash from Ford over its current investment towards the 2030 target.

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.”

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He has weakened the plan to phase out gas boilers from 2035 so that homeowners in England will not have to switch to heat pumps unless they sell on their property.

Patrick Harvie is set to unveil the Scottish Government’s ambitious strategy to decarbonsie heating soon and is shaking up energy efficiency ratings that will downgrade gas boilers in the ratings.

Mr Sunak has also announced he is scrapping policies to force landlords in England to upgrade the energy efficiency of their properties.

The PM also said he was scrapping recycling schemes – raising questions over the Scottish Government’s deposit return scheme, which is now set to be delivered in tandem with the UK Government.

First Minister Humza Yousaf said the U-turn was “unforgivable”, adding that it was “time for climate action and ambition”.

Mr Yousaf added: “The UK Government is on the wrong side of history. I’d urge them to rethink.”

Read more: Analysis: Has something changed in the water since COP26?

The Prime Minister claimed that the UK “leads the world on net zero”, despite statutory advisers, the Climate Change Committee warning earlier this year that Britain “has lost its clear global leadership position on climate action”.

But the strategy will be viewed as wholly political ahead of next year’s general election, where he is expected to lose the keys to Downing Street – with climate policies regarded as some within the Tory party as a vote-loser.

Speaking at Downing Street, the Prime Minister said he is acting because if the UK continues with its current strategy “we risk losing the consent of the British people” and “might never achieve our goal”.

Mr Sunak said he did not want to “impose such significant costs on working people” to achieve net zero, “without a properly-informed national debate”.

He added that “we need sensible green leadership” and a “more pragmatic, proportionate and realistic” approach to tackling the climate crisis.

Mr Sunak insisted the UK was already ahead of allies in reducing emissions and could not impose “unacceptable costs” on British families.

Read more: Net zero U-turn: Rishi Sunak has 'thrown in towel' on climate crisis

“The risk here to those of us who care about reaching net zero, as I do, is simple: if we continue down this path we risk losing the consent of the British people,” he said.

“And the resulting backlash would not just be against specific policies but against the wider mission itself meaning we might never achieve our goal.

“That’s why we have to do things differently.”

Scotland’s Net Zero Secretary, Mairi McAllan, said the changes by the Prime Minister are “devastating for our environment, constitute complete economic illiteracy, and undoubtedly have serious implications for Scotland’s climate ambitions".

The SNP minister said it was an “unforgivable betrayal of current and future generations”.

Piers Foster, chairman of the Climate Change Committee, warned the announcement was “likely to take the UK further away from being able to meet its legal commitments”.

He added: “More action is needed and we await the Government’s new plan for meeting their targets and look forward to receiving their response to our progress report, expected at the end of October.”

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.”

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 added: “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.”

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