Ms Mowlam, Minister for the Cabinet Office, said that she had acted for "the simple reason that my husband is out of work". "I would like to see what the future holds and we always have to plan for the future in politics," she said.
She fuelled speculation that she could quit her job by saying that she would not break government rules which prevent ministers publishing while still in the Cabinet.
Ms Mowlam told ITV's Jonathan Dimbleby programme yesterday: "I have written nothing, I have taken no money and I don't see anything wrong with what I have done. Tony [Blair] knew what I was doing. I have signed nothing and I have no intention of doing so in government." She added: "Let me make clear what I was doing is looking to the future, I have no intention of leaving the Cabinet, no intention of changing my job. I will stay there as long as I am able to."
Westminster had been awash with reports that Ms Mowlam, who is said to be unhappy at losing the Northern Ireland portfolio to Peter Mandelson, had agreed to a pounds 350,000 deal with HarperCollins. The Prime Minister, it has been said, might not be too sad to see her go.
Asked if she still enjoyed the Prime Minister's full support, Ms Mowlam responded: "Tony and I get on very well, contrary to what is in the papers."
Mr Blair's endorsement, however, has been less than ringing. Asked about the matter during the European Union summit in Helsinki last week, he said: "I would be sorry to lose her - but clearly I hope I'm not."
Any book Ms Mowlam writes for the kind of money being mentioned would be expected to be a "warts and all" account of the highly delicate peace talks during her two years as Secretary of State for Northern Ireland, and could also contain details, potentially embarrassing to Downing Street, of how she was removed from the post.
A Downing Street spokesman made it clear yesterday she could not write a book while still a cabinet minister. He said: "The Prime Minister said there was nothing improper in discussing a future book, but there is no question of her writing it while she is still in government, or taking any money for the book deal while she is in government."
As well as uncertainty over her future in the Cabinet, friends say that Ms Mowlam, 50, is beset by very real personal financial problems. Her husband Jon Norton, in his early fifties, has been unable to find another job since losing his pounds 70,000-a-year post with the Bank of New Zealand. Mr Norton supports two children from a previous marriage, and he and Ms Mowlam are said to be faced with the prospect of having to sell their home in north London.
Ms Mowlam's cabinet salary of pounds 90,000 would normally suffice to buy another property in the capital. However, friends say mortgage repayment would be a problem if she were to be dropped from the Cabinet at the next reshuffle.
Ms Mowlam's political demise has been spectacular in both scale and pace. Following the Good Friday Agreement, an opinion poll showed that she was the most popular politician in Britain. At the Labour Party conference last year her standing ovation was as long as Mr Blair's for his speech.
But the Ulster peace process reached an impasse and there was a public falling out between Ms Mowlam and the Ulster Unionists. Briefings started to be given against her, and it soon became clear that Mr Blair no longer saw her future in Northern Ireland. Her rearguard action to stay in the post failed. She wanted the health portfolio, but was given the Cabinet Office job instead.
Stories began to surface of her frustration at this comparatively limited role, and Mr Blair's appointment of her as the new "poverty tsar" has done little to mollify her, friends say.
Steve Richards, Review, page 3Reuse content