Annabel's nightclub, the exclusive Mayfair haunt of aristocrats and celebrities, has emerged as a backer of the interests of both rivals for the Conservative leadership contest.
The shadow Home Secretary, David Davis, lists Robin Birley, who runs Annabel's, as a supporter on the House of Commons register of members' interests. And one of David Cameron's closest allies, Michael Gove, the new Conservative MP for Surrey Heath, lists financial support from Annabel's for his general election campaign.
The club company gave the Surrey Heath Party £2,000 in April, according to figures released by the Electoral Commission.
Mr Birley, whose father Mark set up the club in 1963, has chartered a private helicopter for Mr Davis's campaign, although the leadership candidate is not a member of Annabel's.
But Mr Gove said: "I've known Robin Birley for a very, very long time and he kindly agreed to support my candidacy.
"He's a great guy and I know that he has helped David Davis in the leadership election.
"I have been to Annabel's for a number of events hosted by other people, but I'm not myself a member."
Mr Birley said he was a strong supporter of Mr Davis. "I wish I could do more for him. I have met him four or five times and I have liked him each time. He is the opposite of Blair.
"Michael Gove is a friend of mine. I hope in years to come he will be a leader and I wish him well. This is a brilliant mixture. I wish he was a Davis supporter, but if Mr Cameron wins I'm glad he has Mr Gove with him."
The club gained renewed fame earlier this year, when it was the scene for one of David Blunkett's escapades.
The club, which is based in a Berkeley Square basement, is London's most famous society haunt. Former guests include Richard Nixon, Frank Sinatra and the Queen.