When Boris Johnson was at university he had most in common with the Green Party, the London Mayor revealed in an interview on London Live today.
Johnson, who has spent six years as the Conservative mayor of the capital, said that his father, environmentalist Stanley Johnson, had influenced his views and this led to him spending his informative years worrying about the environment.
Speaking to the editor of The Independent, Amol Rajan, on London Live's weekly politics show Power Lunch, he said: "When I was growing up I was very concerned about the environment, I still worry a lot about the environment, you may not believe this but I do.
"At university I would probably have regarded myself as more of a Green to begin with."
The revelation came as Johnson was asked by Rajan why he joined the Conservative Party and the exact moment when he decided to become a Tory.
According to Johnson, the moment came during the miners' strikes in the 1980s when he was a member of the JCR.
He said: "I became a Conservative when it was the height of the miners' strike."
"There were kids going round from fee paying schools collecting money for the miners led by Arthur Scargill, and I suddenly realised what a load of absolute nonsense it was."
He said: "The pits were fundamentally uneconomic and it suddenly struck me that these people were not being levelled with."
He added that: "You shouldn't make a god or a fetish of the market, but the market is there as the most effective way of satisfying human wants."
You can watch the whole interview on London Live's 'Headline Interview 'at 8pm this evening on Freeview channel 8 or online at londonlive.co.uk