Rishi Sunak is considering watering down policies to tackle the climate emergency as he seeks to take a “proportionate and pragmatic” approach to achieving net zero amid cost-of-living pressures.

The Prime Minister said he does not want to heap “hassle” or extra costs on to families as Conservatives on the right of the party pressure him to weaken commitments to possibly win back voters.

Downing Street insisted Mr Sunak is committed to the ban on selling new petrol and diesel cars from 2030 after he declined to give the same assurance himself.

But No 10 made clear that ministers are scrutinising existing net zero pledges “in light of some of the cost-of-living challenges”, citing the potential for technological advances.

Some Tories have been calling for Mr Sunak to delay climate pledges after the party narrowly held on to Uxbridge and South Ruislip in last week’s by-election, with Labour’s failure to win being attributed to the expansion of London’s Ultra Low Emission Zone (Ulez) scheme.

Mr Sunak said he does not want to add to the pressure households are experiencing from high inflation amid a challenge to get the UK to net zero on carbon emissions by 2050.

“Actually I’m standing up for the British people because I’m also cognisant that we’re living through a time at the moment where inflation is high,” he told broadcasters who asked about the Conservative pressure during a visit to Worcestershire.

We’re going to make progress towards net zero, but we’re going to do that in a proportionate and pragmatic way that doesn’t unnecessarily give people more hassle and more costs in their lives

“So, yes, we’re going to make progress towards net zero, but we’re going to do that in a proportionate and pragmatic way that doesn’t unnecessarily give people more hassle and more costs in their lives – that’s not what I’m interested in and prepared to do.”

Asked whether he is continuing with the target for banning new fossil fuel car sales, Mr Sunak insisted “We’re going to keep making progress towards our net zero ambitions”, but did not explicitly back it.

The Prime Minister’s official spokesman later said it “remains our commitment”, but added: “It is right that, if the situation changes and new technology evolves, we keep our approach under review and make sure that it is the right one.

“Equally, at a time of global high inflation, which is hitting the public hard, we need to make sure that we’re getting the balance right.”

The Times has reported that an “Aston Martin exemption” could be added to give smaller car manufacturers more time to switch to electric vehicles.

No 10 said the commitment to phase out gas boilers from 2035 remains but that “how technology evolves” is being considered ahead of the deadline.

After Housing Secretary Michael Gove indicated that a deadline to improve the energy efficiency of private rented homes could be relaxed, Mr Sunak’s spokesman said “wider developments in energy efficiency and the private rental sector” have to be considered.

“That’s to ensure that the cost and circumstances relating to energy efficiency improvement are fair and proportionate to landlords and tenants,” he added.

The official stressed that low-traffic neighbourhoods must “work for local people” and involve “extensive consultation”, in response to suggestions that they could be restricted.

Former business secretary Sir Jacob Rees-Mogg and Danny Kruger, co-leader of the New Conservatives group of Tory MPs elected since the Brexit referendum, have been urging the Prime Minister to reconsider the deadlines for green initiatives.

Sir Jacob said that scrapping “unpopular, expensive” policies would be a “real opportunity” and proposed getting rid of the 2030 ban announced during Boris Johnson’s premiership.

But Mr Sunak has also faced accusations from some quarters of the Conservative Party of environmental apathy, with Tory peer Lord Zac Goldsmith resigning and accusing the Prime Minister of being “uninterested” in the environment.

Friends of the Earth said ministers should provide financial support to individuals so they can make greener switches, arguing that people on lower incomes are most affected by climate breakdown.

Science head at the climate group Mike Childs said: “Treating climate action as a political fault line is inexcusable, but even more so when deadly heatwaves and wildfires are tearing across Europe, America, and Asia.”

Batting for the Government with a round of morning broadcast interviews, Foreign Office minister Andrew Mitchell was initially unclear about the 2030 ban until he insisted, after coming under pressure, that it “will remain in place”.

But asked on BBC Radio 4’s Today programme if it will remain that way, he said: “Well, all I can tell you is it is in place”, but when challenged again said: “Well, I’m afraid I can’t prophesise for the future.”

He denied the suggestion that it may not stay for the rest of the term of this Government, saying: “That is not what I am saying. I am saying that it is in place and it remains in place.”

Meanwhile, London Mayor Sadiq Khan was sticking by his policy of expanding the £12.50 daily charge for vehicles that fall short of emissions standards to the capital’s suburbs.

Labour leader Sir Keir Starmer had urged him to “reflect” on the policy designed to cut air pollution after the party failed to seize the Uxbridge and South Ruislip seat by 495 votes.