Rishi Sunak has been accused of a “dereliction of duty” after Downing Street said that he would not be attending the COP27 summit in Egypt.
It will take place from November 6 until November 18 a year on from COP26 in Glasgow.
No 10 insists that the UK will be “fully represented” by Alok Sharma, president of COP26.
Officials also confirmed the demotion of environment minister Graham Stuart, who was stripped of his entitlement to attend Cabinet.
Labour’s shadow climate change secretary Ed Miliband described it as a “massive failure” of climate leadership.
A Downing Street spokeswoman stated that Sunak is focusing on domestic issues, including preparations for the autumn budget.
“The Prime Minister is not expected to attend COP27 and this is due to other pressing domestic commitments including preparations for the Autumn Budget,” she said.
“We remain committed to net zero and to leading international and domestic action to tackle climate change. The UK is forging ahead of many other countries on net zero.
“We will obviously continue to work closely with Egypt as the hosts of COP27 and to make sure that all countries are making progress on the historic commitments they made at the Glasgow climate pact.”
The Scottish Greens warned that the decision for Sunak not to attend sends a “very dangerous message to the rest of the world about the planet.
Mark Ruskell, the party’s energy and environment spokesperson, insisted that Sunak should not be “hiding” under a Downing Street desk.
“Rishi Sunak’s failure to go to COP27 is unforgivable, reckless and should sound alarm bells across the globe about the kind of climate denying prime minister he may turn out to be,” he said.
“Given the historical part it has played in creating the crisis, the UK should be at the front of the queue offering bold, transformational leadership on solving the climate emergency, not hiding under a Downing Street desk.
“It is a dereliction of duty and abdication of his responsibility and sends a very dangerous message to the rest of the world that when it comes to our planet, he cares less about the next generation than he does about the next general election.”
Ruskell described it as “shameful” for the UK Government to continue drilling for oil.
He said: “Theresa May, Boris Johnson, Liz Truss and now Rishi Sunak will go down in history as being the prime ministers who robbed our children of their futures, the ones who drilled for more oil and gas but then couldn’t be bothered to turn up to explain why.
“It is utterly shameful and puts our net zero commitments at very real risk. There must be a general election now to get them out of power before the lights go out for good.”