Prime Minister David Cameron has said he is "too busy running the country" to sue over allegations made in Lord Ashcroft's biography of him.
Last week, the Daily Mail serialised the book, Call Me Dave, which was co-written by former Sunday Times political editor Isabel Oakeshott.
The allegation that Cameron inserted "a private part of his anatomy" into the mouth of a dead pig when he was a student proved one of the more headline-grabbing extracts.
And a former News of the World political editor said the tabloid would not print the allegation because it "would not have passed [its] basic standards".
Oakeshott, meanwhile, said on Channel 4 News that she and Ashcroft "couldn't get to the bottom of" the claim, but “merely reported the account that the source gave us”.
Asked on Sky News whether he would be taking legal action over the book, Cameron said: "No. I'm too busy running the country, taking decisions, getting on with work.
"If you do a job like this, you do get people who have agendas and write books and write articles and write all sorts of things. The most important thing is not to let it bother you, get on with the job."