Friends and family gathered by her hospice bedside after life support was withdrawn and she developed breathing difficulties.

Dr Mowlam, 55, wrote a living will some time ago requesting that she should not be kept alive artificially if there was no hope of recovery.

She is being cared for at the Pilgrims Hospice in Canterbury. She was transferred there this week from King’s College Hospital, London.

Dr Mowlam had a brain tumour diagnosed in 1997. She made a full recovery but friends said that in recent months she had fallen ill again.

“Mo’s condition has been deteriorating for some time, but recently the radiation treatment she received for her brain tumour started to have side- effects,” one friend said.

“She started to lose her balance, then she fell over and hit her head. She has not regained consciousness since.”

Marjorie Mowlam, whose father was an alcoholic, was the only child of three to go to university. From this humble beginning she rose to become, for a while, the most popular politician in the country, widely praised for her role in helping to secure republican backing for the Good Friday agreement.

The public warmed to her informal manner and sympathised with her illness. Treatment for the tumour forced her to wear a wig which she took off in tense meetings to break the ice.

She had cancer diagnosed while working towards Labour’s landslide victory in 1997. She kept the illness secret. However, a few weeks before the May elections the tabloid newspapers published unflattering pictures of a puffy Dr Mowlam and accused her of bingeing on sweets.

Her revelation that she was taking steroids for a brain tumour led to greater standing in the public eye, as she had never stopped campaigning, visiting 52 constituencies.

She took a huge political gamble in 1998 by bravely entering the infamous Maze prison to speak to convicted paramilitaries when their backing for the peace process wavered.

She spoke to the prisoners face to face for 60 minutes and two hours later the paramilitaries’ political representatives announced that they were rejoining talks. The Good Friday agreement was signed months later in April that year.

Adulation for the woman once dubbed “St Mo” reached its peak at the following Labour Party conference. Tony Blair’s tribute to “our one and only Mo” prompted a two-minute standing ovation in the middle of his conference speech.

She believed this show of popularity “upstaged” the leader and was the start of her political demise — a charge denied by the Prime Minister.

But the truth was that her ministerial star was already beginning to wane.

Poor relations with mainstream Unionists meant that she was never quite at the centre of negotiations. She lost the trust of David Trimble, the Ulster Unionist leader, early in the job. He believed that she was too sympathetic to the nationalists and insisted that he would deal only with Tony Blair or Jonathan Powell, his chief of staff.

By the time that President Clinton visited Northern Ireland after the deal was signed, her critics say that she was reduced to serving the tea.

She lost the job to Peter Mandelson in 1999 when she was demoted to the marginal role of Cabinet Office Minister, having turned down the more illustrious job of Health Secretary. She left Parliament at the next election, giving up the Redcar constituency she had held for 14 years.

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