The Tory MP in charge of overseeing the government's climate change policies has suggested humans may not be the cause of global warming.
Tim Yeo said 'natural phases' may in fact be the cause.
His comments, reported by the Daily Telegraph, sparked surprise among pundits, concern among environmentalists and celebration among climate change sceptics.
Writing in the Telegraph, climate change-sceptic James Delingpole said Yeo had taken the "first tentative step on the path to redemption."
Yeo was an environment minister under John Major and is now chairman of the influential Commons Environment Select Committee.
The committee is in charge of overseeing the government's environmental policies.
His comments came as a surprise because he has previously led the change to 'decarbonise' British energy, and has pushed for radical action to cut the UK's emissions.
According to a recording obtained by the Telegraph, Yeo told a gathering of Russian investors: "On climate change, the first thing to say is that it does not represent any threat to the survival of the planet.
"Not at all.“
He went on: "Although I think the evidence that the climate is changing is now overwhelming, the causes are not absolutely clear.
"There could be natural causes, natural phases that are taking place.”
He later claimed his comments had been taken out of context.
“It is highly probable that human activity has led to a big increase in the concentration of greenhouse gases in the atmosphere and highly probable that that is changing the climate,” he said.