Jeremy Corbyn has accused Boris Johnson of "failing so spectacularly" on climate change, in a heated clash at Prime Minister's Questions.
And he went further, accusing the prime minister of reviving his "climate change denial" beliefs and claimed he was previously a "climate sceptic".
But the prime minister deflected criticism, branding Mr Corbyn's comments "beyond satire", adding: "This is the first major economy in the world to have set a target of carbon neutral by 2050."
Climate change again took prominence in the Commons, after former climate and energy minister Claire O'Neill was fired last week as the president of the of the 2020 United Nations Climate Change Conference (COP26), which is due to take place in Glasgow in November.
Mr Corbyn quoted Ms O'Neill's own words in the Commons, arguing: "There has been a huge lack of leadership and engagement from this Government".
He went on: "Considering his monumental failure in advance of COP26, isn't it really just a continuation of his climate change denial statements that he was regularly making up until 2015?"
Mr Johnson said Mr Corbyn was "talking absolute nonsense" and defended the government's agenda, adding: "We lead the world in going for a zero carbon approach. His own approach is utterly unclear and has been condemned by the GMB as a disaster for the UK economy.
"He would confiscate people's cars and prevent them from having foreign holidays."
Mr Corbyn countered that the PM has a "very vivid imagination", adding: "Unfortunately his vivid imagination seems to have taken over from his memory because he might recall saying that climate change is a primitive fear without foundation."
Responding, Mr Johnson said: "If you look at what this Government is achieving and already has achieved on climate change it is quite phenomenal."
He dismissed Mr Corbyn's words, saying: "All he would produce I'm afraid is a load of hot air."
Sacked Ms O'Neill heavily criticsed Mr Johnson's approach to climate change, saying he was "miles off track" in setting a positive agenda for the summit in November.
In a letter to Mr Johnson, where Ms O'Neill reveals she was sacked by Mr Johnson's adviser Dominic Cummings on Friday, she wrote: "You promised to ‘lead from the front’ and asked me what was needed: ‘Money, people, just tell us!’ Sadly these promises are not close to being met."
She added: "This isn’t a pretty place to be and we owe the world a lot better."
Mr Corbyn noted two former Conservative leaders had turned down Ms O'Neills former job, joking "maybe it could be third time lucky" as he suggested former Tory leader Sir Iain Duncan Smith for the role - who shook his head at the suggestion.