British international environment minister Zac Goldsmith resigned on Friday, saying Britain had lost its claim to a global leadership role on climate and Prime Minister Rishi Sunak was "uninterested" in environmental issues.
Goldsmith is seen as an ally of former prime minister Boris Johnson, placing him on the opposite side to Sunak of a deep divide in the ruling Conservative Party.
"The problem is not that the government is hostile to the environment, it is that you, our Prime Minister, are simply uninterested," said Goldsmith, who sits in parliament's upper chamber and held the title of Minister of State for Overseas Territories, Commonwealth, Energy, Climate and Environment.
Sunak's office did not immediately comment.
Britain had: "visibly stepped off the world stage and withdrawn our leadership on climate and nature," Goldmsith's resignation letter posted on Twitter said.
That echoes a report published earlier this week by the government's climate advisers, who said Britain had lost its position as a global leader on climate action and was not doing enough to meet its mid-century net zero target.
The Climate Change Committee report also highlighted a recent decision to commission a new coal mine and support for new British oil and gas production.
Before Sunak became leader, Britain won international plaudits in 2021 for brokering a global climate pact at the COP26 summit in Glasgow. However shortly after taking power Sunak said he would not attend the 2022 COP summit, before changing his mind when faced with criticism.
Nevertheless, Sunak has set up a new government department in charge of the country's net zero plan, and has highlighted the importance of growth in green industries to Britain's economic future.
On Friday, shortly after Goldmsith's resignation, the government announced a new multi-million pound fund to create and restore wildlife-rich habitats.
Some of Johnson's allies have been increasingly critical of the government since he resigned from parliament earlier this month in protest over a report that found he had deliberately mislead lawmakers about COVID lockdown parties.
Goldsmith was on Thursday reprimanded by a parliamentary committee which criticised the behaviour of a group of Johnson allies for seeking to intimidate the panel that criticised his conduct during lockdown.
