Sadiq Khan has told the United Nations that cities like London can be “climate titans” - as he attacked Rishi Sunak for “delay and dither” on net zero goals.
Speaking at the UN Climate Action summit in New York, the London mayor criticised the prime minister for “backtracking” on the UK’s environmental commitments.
Mr Khan sought to distance the capital from the rest of Britain, as he argued that London and other global cities are “the ones willing to take the tough calls”.
He told world leaders: “It’s easy to get angry at the delay and dither from some quarters, and I know businesses and millions of people feel let down by news from my own country that our prime minister is now backtracking on the UK’s climate commitments.”
The mayor was speaking minutes after Rishi Sunak had finished a Downing Street press conference, in which he outlined a “new approach to achieving net zero”.
The PM accused previous governments of trying to reach net zero “simply by wishing it”, and warned that sticking with the status quo on climate pledges would “risk losing the consent of the British people”.
Mr Khan - who has said he is using his trip to New York to “bang the drum” for London - said in his three minute speech at the UN summit that cities can play a crucial role in helping the planet to reach net zero carbon emissions.
He pointed to his expansion of the Ultra low emission zone (Ulez) as one example of cities “leading the charge” on environmental action.
“Only last month, London implemented the world’s largest clean air zone, and let me be frank - doing this wasn’t easy,” he said.
“But the time for action is now, which is why we’re also investing in green jobs, public transport and clean energy.”
The mayor reiterated that London remains committed to achieving net zero by 2030, rather than the UK’s national target of 2050.
He added: “Cities can be climate titans, using our might and muscle to make a decisive difference, in this decisive decade.”
In a message to fossil fuel companies, Mr Khan said: “If you don’t change and commit to the green transition, you risk being consigned to the past.
“The choice you face is simple - get on board, or get left behind, as we race to a greener age.
“And governments should be helping businesses to do that, not putting obstacles in their way.”
The mayor concluded his remarks by saying: “To all those working to secure the fate of our civilisation, the cities of the world are with you.
“We will do everything we can to keep the promise of 1.5 alive, and we’ll continue to call on nations to give us more power and resources to win the fight.”
Mr Khan was referring to the promise set out in the Paris Agreement of 2015, which committed nations to pursuing efforts “to limit the temperature increase to 1.5°C above pre-industrial levels”.
Downing Street’s press release on Mr Sunak’s changes to green policies states: “The Prime Minister has made clear that the plans to meet net zero will only succeed if public support is maintained or we risk losing the agenda altogether, unable to meet our goals.
“The UK will remain the country with the most ambitious, stringent de-carbonisation targets in the world even after these changes are made.”
Mr Khan was meanwhile accused of hypocrisy for flying to New York to attend the summit by Conservative mayoral candidate Susan Hall.
She tweeted: “Why have you flown halfway across the world to attend a climate summit - was that necessary? Seems more than a bit hypocritical.”
The mayor told the Standard last week that he travels to global gatherings “only in exceptional circumstances”, and instead participates virtually where possible.