by Our News Desk

DOWNING STREET refused to comment yesterday after Tory Lord Ashcroft accused David Cameron in a new book of lurid behaviour while at Oxford University.

No 10 said it would not “dignify” the claims of the billionaire tax exile, once the Tories’ biggest donor, serialised in the Daily Mail ahead of the publication of biography Call Me Dave.

The Prime Minister’s official spokeswoman said: “The author has set out his reasons for writing the book” — referring to the tax-dodger’s claims that he had been offered a Cabinet post by Mr Cameron but was then snubbed.

Among the sensational claims it was alleged that Mr Cameron had taken drugs and that he had put a “private part of his anatomy” into a dead pig’s head as part of a joining ritual for a dining club.

The book claims that an MP said he had seen a photo of the disgusting act when Mr Cameron attended the Piers Gaveston dining club — named after Edward II’s lover and known for its debauchery.

Multimillionaire Mr Cameron was already known to have been a member of the Bullingdon Club, a drinking club known for wrecking rooms. Their antics even shocked one Tory MP who was asked to join but walked out in disgust, saying it was all about “despising poor people.”

Mr Cameron’s official spokeswoman said: “I am not intending to dignify this book by offering any comment.

“The Prime Minister is focused on getting on with the job of running the country.”

Lord Ashcroft also claimed that Mr Cameron knew of his “non-dom” legal tax-dodging wheeze in 2009. The PM had previously insisted he was unaware until just before the 2010 election.

Co-author Isabel Oakeshott insisted the book was not a “revenge job” over Mr Cameron’s snub of Lord Ashcroft.

She argued that it was planned to publish the book now rather than before the election, when it would have “caused far more damage.”