Conservative Party leadership contenders have been urged to ignore the “siren voices” pushing them to ditch the UK government’s plan to achieve net zero carbon emissions by 2050.

A group of net zero sceptics on the Tory back benches are hoping to move Boris Johnson’s would-be successors away from green policies, as climate change shapes up to be a major battle in the contest to choose the next prime minister.

Senior Tory MP Steve Baker – founder of the Net Zero Scrutiny Group of backbenchers – has suggested that he would push for the next PM to dismantle the government’s climate agenda.

Some in the party fear top contenders such as Nadhim Zahawi and Liz Truss could be pressured into prioritising tax cuts over investment in renewable energy, as well as committing to an expansion of oil and gas production.

Tory peer Zac Goldsmith, who has attacked Rishi Sunak’s environmental record, told The Independent it would be better to have a Labour government than a leader who “deprioritises” action on net zero.

Lord Goldsmith added: “It would be a catastrophic error for Conservatives to select a candidate who deprioritises these issues, but if they do, then we can only hope voters replace the party at the [next] available election.”

Chris Skidmore, a senior backbencher who chairs the Tories’ rival Net Zero Support Group, has vowed to push candidates to uphold Britain’s climate commitments.

“We can’t put net zero at risk,” the former energy minister told The Independent. “I devoutly believe net zero is a vote winner. If we go soft on net zero, then a candidate has to know they will struggle to win a general election.”

Warning contenders to ignore the “siren voices” of the Net Zero Scrutiny Group, Mr Skidmore pointed to recent polling which shows that ditching net zero could cost the Tories 1.3 million votes.

“I’m absolutely determined to make sure net zero policies are put forward,” said the MP, who signed the commitment to achieving zero carbon emissions by 2050 into law when he was energy minister in 2019.

Mr Skidmore added: “It’s a policy that unites the red wall in the north and blue-wall seats in the south, because there are plans to deliver massive investment in renewable energy in red-wall seats.”

However, Mr Baker and his ally Craig Mackinlay MP, who is chair of the Net Zero Scrutiny Group, are hoping that policies aimed at achieving net zero by 2050 can be rolled back.

Mr Baker, who on Friday withdrew his leadership pitch and backed Suella Braverman, said on Thursday that he wanted to see more domestic gas production and an end to the drive to boost renewable energy.

“We are at risk from extreme green policies,” he told The Guardian – saying he believed there was “no short-term threat” from the climate crisis.

Mr Mackinlay told The Independent: “I will require a new leader to bring a new realism to the net zero enterprise that reflects the changed world [in terms] of the need for energy security and lower costs.”

Earlier this year, a group of 20 MPs in the sceptics’ group – including former ministers Esther McVey and Robert Halfon – called for green levies to be scrapped from energy bills. The levies help to pay for investment in renewable energy.

MPs in the group have also pushed for further cuts to fuel duty, despite warnings that this would undermine the move towards electric vehicles. Mr Mackinlay has questioned the government’s target to phase out the sale of new petrol and diesel vehicles by 2030.

Environmentalists are also worried by cabinet minister Jacob Rees-Mogg’s recent call for “every last drop” of oil and gas to be extracted from the North Sea, and his desire to see the temporary ban on fracking lifted to boost shale gas production.

Green MP Caroline Lucas has warned against more North Sea drilling, and urged all those bidding to be the next PM to rule out approval for a new deep coal mine in Cumbria, after the decision was delayed by Mr Johnson’s resignation.

Ms Lucas said: “My question for Tory leadership contenders is crystal clear: will they approve a new climate-busting, backward-looking, business-wrecking, stranded asset coal mine in Cumbria? Yes or no?”

Rishi Sunak is the most high-profile figure yet to throw his hat into the ring. The former chancellor has remained largely quiet on climate change and has been criticised over government moves to back North Sea oil and gas exploration.

Among the other contenders, Ms Truss has previously cut subsidies for solar farms, describing them as “a blight on the landscape”, and Mr Zahawi made £1.3m from a second job at an oil company while working as an MP, according to an investigation by the Daily Mirror last year – though there is no suggestion of any illegality.

Lord Goldsmith warned on Twitter earlier this week that “most of the likely contenders are people who, on the whole, couldn’t give a s*** about climate and nature”.

The Conservative peer, who remains an environment minister, attacked Mr Sunak over his record on the environment and compared the Tories’ Commons leader Mark Spencer to Brazilian populist president Jair Bolsonaro.

“Rishi Sunak has evidently agreed to make Mark Spencer the next Defra sec of state,” said Lord Goldsmith – claiming the Commons leader had blocked measures to protect biodiversity and animal welfare. “He will be our very own little Bolsonaro.”

Mr Goldsmith denied being motivated by personal animosity towards Mr Sunak – but said he had not made “believable commitments to continue our environmental role globally”.

Joshua Marks, a senior researcher at think tank Bright Blue, which champions liberal Conservatism, said there was a “real risk” that pressure from sceptics within the party could mean environmental policies get lost “under the rug” in the leadership campaign.

In the context of the cost of living crisis and the war in Ukraine, he said, climate change could appear politically “less sexy” than the push for a boost in energy supply – despite the fact that the issues are interconnected, with fossil fuel prices rising in the wake of the Russian invasion.

Alexander Stafford, Tory MP for Rother Valley in Yorkshire, said the Net Zero Scrutiny Group had been trying to “drum up support” among red-wall MPs in the north of England and the Midlands.

But Mr Stafford said the majority of those MPs were still persuaded, like him, that investment in renewable energy would boost jobs and growth. “There is debate... Some people still say binning all the green stuff will win us votes,” he said.

“But I don’t want anyone to feel that by abandoning these [net zero] ideas they are going to win over people in the party,” he added. “I would be very concerned if any candidate goes against the net zero agenda.”

Around 130 Tory MPs are members of a wider group, the Conservative Environment Network (CEN), which advocates support for the general principle of net zero. Sam Hall, director of the CEN, warned candidates not to “squander” the steps already made towards reaching the net zero goal.

Liberal Democrat leader Ed Davey said the potential influence of the Net Zero Scrutiny Group on the leadership contest was “deeply concerning”. “Undoubtedly there are still some elements within the Conservative Party that still ignore the science,” he told The Independent.

Mike Childs, head of policy at environmental group Friends of the Earth, said he was hopeful that the Conservatives would see the big picture.

“If they do get sucked down and listen to siren calls by some of the more extreme in the Conservative Party, then they’ll be demonstrating that they’re not fit to be prime minister,” he said.