Sir Christopher Meyer said yesterday that he had no plans to quit as chairman of the Press Complaints Commission as he hit back at John Prescott's accusation that he was a "red-socked fop" whose gossipy memoirs of his life as British ambassador to the US and aide to John Major made him unfit for the job.

In a letter to the deputy prime minister, Sir Christopher said he would stay in the post, arguing that he did not believe the serialisation of his book, DC Confidential, in two newspapers, including the Guardian, placed him in a conflict of interests. "I intend to continue to carry out my duties as I have sought to discharge them in the last two-and-three-quarter years: impartially, independently and effectively," he wrote to Mr Prescott.

A spokesman for the deputy prime minister said Sir Christopher's bullish defence "was not satisfactory and does not answer the questions".

But the PCC chairman repeated that he had not breached the rules. "It is important to emphasise that the commission consists of 17 members, 10 of whom - the clear majority - are members of the public. Its decisions are made not by me alone, but by the PCC as a whole," he wrote.

In a sideswipe at the prime minister's wife, Sir Christopher also responded to complaints that he had intruded on Sir John Major's privacy by describing scenes in the No 10 bedroom.

"Sir John Major's underwear does not feature anywhere in my book. What is more, the scene concerned first appeared last year in the book The Goldfish Bowl by Cherie Booth and Cate Haste," he wrote.

Last night the former Europe minister, Denis MacShane, said it was "not for Sir Christopher to announce that he will sit permanently as chairman of the PCC when it is clear that he has lost the confidence of a great many people in public life. Criticising Cherie Booth hardly adds to Sir Christopher's lustre."