Mo Mowlam's standing ovation during a key Labour party conference speech by Prime Minister Tony Blair triggered a campaign against her, the late Northern Ireland Secretary's husband suggested yesterday.
Ms Mowlam, who died in August, complained of being "knifed in the back" because of her popularity in an autobiography.
Peter Mandelson, who succeeded her as Northern Ireland Secretary, was also accused of campaigning for the job while she was in post in her memoir Momentum.
Husband Jon Norton said the problems started after the Coventry-born MP received the ovation during the Prime Minister's speech at Labour's 1998 party conference.
"It was certainly the beginning of adverse stories in the paper after that," he said. "Who precisely was briefing I don't know.
"But I remember we had (US Secretary of State) Madeline Albright visit us just after that and she was warning Mo that that was probably the most dangerous thing that had ever happened in her political career."
Mr Norton was speaking ahead of a special memorial service for his late wife at London's Drury Lane Theatre last night.