The much-anticipated diaries of spin doctor Alistair Campbell may have disappointed politics junkies with their lack of information about the decade-long feud between No 10 and No 11 Downing St, but his reminiscences still contain some interesting insights into the Blair years.

One such nugget is the revelation that the Prime Minister’s wife and a former gay Radio 1 DJ helped persuade a senior Tory MP defect to the Labour party because he was about to be sacked for supporting gay rights.

Shaun Woodward was appointed to the Cabinet by Gordon Brown last week, as Secretary of State for Northern Ireland.

In 1999, however, Mr Woodward was a Tory front bench spokesman on London and MP for Witney.

He rebelled over his party’s continued support for Section 28, which banned local authorities from “promoting” homosexuality in schools.

About to be sacked by party leader William Hague, that Mr Woodward asked to see Cherie Blair, Mr Campbell reveals.

“Cherie popped in and saw him for about 20 minutes, and basically just said he should do what he felt was right.

“He looked like he had been crying. He had put on some weight and was very emotional,” he wrote.

Mr Woodward was joined in his defection to Labour by his wife Camilla, who is a member of the Sainsbury family.

His sister, Lesley, who became a woman after having a sex change six years ago, says she has always supported Labour. He was one of the strongest parliamentary supporters of the Gender Recognition Act 2004.

Mr Woodward became the only Labour MP to have a butler. At the 2001 general election he abandoned his seat, Witney, to run in the safe Labour constituency of St Helens South.

The Witney seat was won by David Cameron.

Mr Campbell also reveals that a gay man, former Radio 1 DJ Paul Gambaccini, helped compose Mr Woodward’s resignation letter.

Before his elevation to the Cabinet, Mr Woodward was Parliamentary Secretary at the Department for Culture, Media and Sport (DCMS), covering creative industries and tourism.

Before working at DCMS, Mr Woodward was Parliamentary Under Secretary of State at the Northern Ireland Office.