Tory leader Kemi Badenoch has dismayed green Conservatives by declaring the UK’s target to reach net zero by 2050 “impossible”.

In a speech on Tuesday, the Conservative Party leader is expected to tell what she says is the “unvarnished truth” that the net zero goal cannot be achieved without “a serious drop in our living standards or by bankrupting us”.

Ms Badenoch will say she is not making a “moral judgement” on net zero or debating whether climate change exists.

But, as she begins to renew party policy, she will say that current climate policies are “largely failing” to improve nature and “driving up the cost of energy”.

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Net zero means cutting emissions of greenhouse gases, which cause climate change, to virtually zero, and absorbing the rest elsewhere.

Scientists say the world must reach that point by 2050 to avoid even worse flooding, wildfires, and other damage – but that action is lagging behind.

The UK has already cut its greenhouse gas emissions in half.

The next half is expected to be more challenging as it requires changes to people’s heating, cars and diet – things that often need upfront costs, but could save people money in the long run with the right government support, advisers have said.

Ms Badenoch’s plans take the Conservative Party to its most sceptical position on net zero yet – a target set in law by Tory Prime Minister Theresa May in 2019.

And it comes at a time when Reform UK is questioning climate science and US President Donald Trump, leader of the second most polluting country in the world, is dismantling nature protections.

Ms Badenoch’s “policy renewal” she is outlining on Tuesday will see shadow cabinet members set core priority questions as a move towards formulating new policy for the party.

Sam Hall, of the Conservative Environment Network of 50 MPs, said it was “a mistake” for Ms Badenoch to have “jumped the gun on her own policy review and decided net zero isn’t possible by 2050”.

He said the Tory leader was right to question Labour’s climate plans, but that the target is driven “not by optimism but by scientific reality; without it climate change impacts and costs will continue to worsen”.

Abandoning the science would risk losing voter’s support, he added.

Four in five Conservative voters in last year’s general election and two thirds of Reform voters thought it was important that the government cared about tackling climate change, according to polling by More in Common.

Shaun Spiers, executive director of thinktank Green Alliance, called it “disappointing” to see Ms Badenoch “turn her back on cleaner, cheaper, homegrown energy”.

“It is even more disappointing to see the leader of the opposition take cues from climate deniers across the pond,” he added, in a veiled swipe at President Trump.

“Net zero is not ‘nice-to-have’, it’s an achievable, evidence-based target designed to protect the UK from the worst impacts of climate change.”

The UK’s Climate Change Committee (CCC), which advises governments on how to reach net zero, said last month the goal is “ambitious” but “deliverable”.

But it also warned as Labour took office last summer that, at that time, just one third of the cuts to greenhouse gases needed to reach an interim 2030 target were covered by a “credible plan”.