Internal Tory tensions over the coalition deal were graphically illustrated when unguarded comments by the man David Cameron beat for the party leadership emerged.

David Davis is said to have approvingly repeated a description of the partnership between Mr Cameron and Liberal Democrat leader Nick Clegg as "Brokeback Coalition".

The former shadow home secretary also allegedly mocked the Prime Minister's vision of the "Big Society" as "Blairite dressing" that was designed to hide his desire to shrink the state.

According to the Financial Times, Mr Davis made his remarks to businessmen, including former colleagues from Tate & Lyle, during a private lunch at the Boot and Flogger wine bar in Southwark, south London, on Thursday.

The MP was overheard saying that Lord Ashcroft, the ex-Conservative Party deputy chairman, had referred to the Government as "Brokeback Coalition" - a reference to the Oscar-winning film Brokeback Mountain, about a gay relationship.

Discussing the Big Society, he apparently made clear his belief that the concept was merely "a Blairite dressing".