Rishi Sunak has vowed to press ahead with watering down key green measures despite intense criticism, because he still believes the UK will hit its net zero target in 2050.

The prime minister defended defying the recommendations of the Climate Change Committee (CCC) and insisted he had “absolute confidence and belief” the country was on track to meet its end goal.

In a BBC radio interview on Thursday morning, Sunak shrugged off suggestions he had ignored the view of the official body that advises governments on reducing emissions.

He said: “I’m very happy to have opinions and advice from everybody, and everyone’s entitled to their view. We’re very confident – being in government, with all the information at our disposal – that we we are on track to hit all our targets.”

Sunak told Radio 4’s Today programme that Margaret Thatcher would have agreed with his rationale, and that it was not right for “working families” to face significant costs as part of the country’s transition to net zero.

But Sunak struggled to provide an explanation for claims he had scrapped measures critics said had never seriously been mooted – such as an alleged tax on meat, compulsory car sharing and forcing households to use seven recycling bins.

“These are all things that have been raised by very credible people,” he argued. When pressed, Sunak was unable to provide evidence that those specific measures had been suggested by anyone and instead said they had been euphemistically advocated for by bodies such as the CCC.

Dismissing concerns that were raised overnight about his plans, Sunak said the UK would still stick to its target of reducing emissions by 68% before 2030 – arguing the government was “pretty much more ambitious than any major economy”.

Sunak also hinted there would be further announcements in other areas to come. “We have to change the way we do politics,” he said.

“You can’t chase the short-term headline – you’ve got to do the things that are right in the long term. That’s not going to be easy. I know I’ll get criticism and flak for it, as you’ve seen over the last day or two.

“But I’m not going to be deterred from doing what I believe is right for the long-term future of our children. That’s what yesterday was about and that’s what I will continue to do.”

In a press conference on Wednesday, the prime minister announced a flurry of U-turns on climate targets – pushing back the ban on purchasing new petrol cars from 2030 to 2035, and delaying the target of eliminating gas boilers.

The move was condemned by industry figures, including the chair of Ford UK, as well as some Conservatives including Boris Johnson and the former environment minister Zac Goldsmith.

Al Gore, the former US vice-president, led international condemnation of what he called a “shocking and really disappointing” decision that had left young people feeling “stabbed in the back”.

Kemi Badenoch, the business secretary, said the move was in response to many firms saying they were not ready for the net zero transition. “We are not just doing this for the fun of it,” she told Times Radio.

In a fiercer rebuttal, Badenoch also suggested on LBC that Goldsmith was so concerned about the environment because he had “way more money than pretty much everyone in the UK”.

Sunak’s green pledges U-turn is designed to open up a clear dividing line with Labour.

Ed Miliband, the shadow net zero secretary, said on Thursday morning the delays would end up costing consumers billions more in the long-run. He argued they would drive up bills and see the potential for a green jobs revolution falter.

John Curtice, one of the country’s leading elections experts, believed Sunak had “picked up the zeitgeist” – particularly among Conservative supporters – by identifying practical issues with the journey to net zero.

Curtice said that while voters would be averse to things that would see their bills grow, it was not clear whether Sunak’s announcement would leave people financially better off in the long-run.