Mo Mowlam has said that people in Whitehall were trying to "put the knife in" following reports that her illness had left her unable to do her job, and admitted that she missed being Northern Ireland secretary.

The Cabinet Office minister also said she was hurt been by newspaper reports at the weekend of a whispering campaign against her - apparently emanating from government sources - suggesting she was incapable of properly carrying out her ministerial duties because of the after-effects of surgery in 1997 to remove a benign brain tumour.

"That was an allegation in a paper at the weekend - unfounded. It hurt a lot," she told BBC Radio 4's Woman's Hour on Thursday.

She pointed out she had not needed any treatment for her illness since July 1997.

"There [are] people that want to put the knife in and this story enables them to do it. It is very difficult to answer," she said.

The Redcar MP insisted she had "no idea" who was responsible for the attacks and made clear that she would not allow them to deflect her from her job.

"If I knew, I would stop it," she said. "All I do is get on with it. I have stopped reading the papers - I go swimming instead in the morning. I find it more useful."

She refused to be drawn on reports that she was unhappy at going to the cabinet office from the Northern Ireland office in Prime Minister Tony Blair's September reshuffle last year, and would have preferred health or the foreign office.

'I will do what Tony tells me to'

"What is true is that I want to be a member of the Cabinet," she said. "I will do what Tony tells me to do or asks me to do and this was the job that was available and contrary to the stuff in the press what I am doing does make a difference."

"I am sure over time, and I hope in the years ahead, I will do other departments, but don't underestimate the job I am doing now. It is one that, if we can deliver the policies, it will make a big difference to the government's future."

She also confirmed that she had applied for a government "grace and favour" apartment while she and her husband Jon Norton - who recently lost his job as a banker - searched for a smaller home.

"I have a husband who is unemployed and the grace and favour flat came vacant and it was available for cabinet ministers," she said.

"I put in a bid and was asked why and I said because we are going to sell the house we are in, which is my husband's old family house, and move downmarket because he has not got a salary coming in to help pay the mortgage.

"Him unemployed, me with my history of a brain tumour means that it is difficult to get another mortgage so we are going to go downmarket and pay for something we hope on the back of the house we sell that we can own.

"Small, but ours."