Rishi Sunak has insisted he is “absolutely not slowing down” efforts to combat climate change as he rejected accusations his government’s legal net zero pledges are at risk of failure despite warnings from his top independent climate adviser.

The Prime Minister is facing a backlash from opponents, climate scientists, campaigners and some within his own party after pushing key dates to clean up transport and heating systems.

But he insisted the UK’s 2050 net zero target remains on track, meaning that more drastic action will be needed in the coming decades for the target to be met.

The PM said he was confident climate targets would still be met when asked if he was prepared for legal challenges against his plans.

He repeated his denial that his move was about playing politics, despite the move being an apparent attempt to draw a clear dividing line between the Tories and Labour ahead of a likely general election next year.

Read more: Rishi Sunak under fire after watering down climate strategy

Speaking on the Today programme, the PM was challenged over several measures he claimed he was scrapping, including the possibility of taxes on meat and compulsory car sharing, after his former environment minister Lord Goldsmith accused him of “pretending to halt frightening proposals that simply do not exist”.

The Prime Minister said: “I reject that entirely.”

“These are all things that have been raised by very credible people about ways to meet our net zero obligations,” he said, citing the Climate Change Committee (CCC) as the source of the proposals, although it never has recommended a so-called “meat tax”.

But the chief executive of the committee, Chris Stark, described them as “straw men suggestions”, telling Today: “He seemed to be cancelling a set of policies that the Government hadn’t announced, which is, I suppose, a political technique.”

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

Mr Stark also refuted the Prime Minister’s assertion that the country was on a path to meet its targets.

He said: “It’s difficult to escape the idea that we’ve moved backwards from where we were when we did our last assessment of progress … in June.”

Even then, the independent body that advises governments on reducing emissions warned the UK was not on track to meet 2030 targets.

Mr Stark said: “It looks like those goals will be even harder to hit with this softer package now around climate policy,” its chief said.

“The key thing is that those goals still remain, the Prime Minister recommitted to them. So I would say that the wishful thinking here is that we have not got a policy package to hit the legal targets that this country has set in law through the Climate Change Act.”

The Prime Minister shrugged off suggestions he was not listening to the independent statutory advisers, the CCC, and emulating his predecessor Liz Truss by ignoring expert advice he did not want to hear.

Read more: Labour would 'relish' general election fight with Tories over net zero

Mr Sunak said: “I’m very happy to get opinions and advice from everybody and everyone’s entitled to their view.

“For those who disagree with me, and there are plenty of people as we can see over the last day or two, lots of people who disagree with me, the questions for them, they should explain to the country why they think it’s right that ordinary families up and down the country should have to fork out five, ten, £15,000 to make the transition earlier than is necessary.”

Pressed on the prospect of legal challenges over his plans, the Conservative Party leader said he had “absolute confidence and belief” the UK will hit its targets, having “consistently over-delivered in all our previous carbon budget”.

He added: “We are absolutely not slowing down efforts to combat climate change. I am very proud of our country’s leadership. We have decarbonised faster than any other major economy in the G7, not a fact you hear reported that often.”

He brushed off a backlash from the car industry, after Ford warned that delaying the ban on new petrol and diesel vehicles would “undermine” its needs for “ambition, commitment, and consistency” from the Government.

He said: “They made those comments before I’d actually stood up and made a speech based on speculation and since then what you’ve had are multiple other car manufacturers, including Toyota last night, welcome what I said.”

Mr Sunak insisted the changes were not about politics, saying he wanted to “change the direction of our country” meaning he had to be “willing to change politics”.