Mrs Collins, the former chairman of the Epping Forest Tory party in Essex, and three other local women from the constituency penned a letter arguing that Mr Norris, who has had a string of mistresses - including a surgeon, a House of Commons secretary and Sheila Gunn, John Major's former personal assistant - was an unacceptable Tory candidate for London mayor. Mr Norris represented Epping Forest until standing down as an MP in 1997.
Although Mr Norris openly admits to having a "tabloid past", the letter helped to swing a selection panel of 20 senior Tories against the former transport minister, who they had earlier placed on the shortlist and was favourite for the nomination.
The party Chief Whip, James Arbuthnot, had the duty of reporting to the committee his views about Mr Norris after seeing him on Friday. He is said to have marked him eight out of ten, while giving the other candidates no more than four.
But the letter hit its mark. Mr Norris angrily dismissed it as contemptible yesterday. Those who signed it included Valerie Metcalfe, another true blue Tory. The signatories claimed that he was completely untrustworthy, and had misled the constituency over his private life when he was selected to fight the seat in a by-election.
The letter said he had lied to them when he had said that he was a happily married family man. It also claimed that his standing in Epping was so low before the last election that if he had not stood down, he would have been sacked by the local party.
His supporters were quick to denounce the Epping Forest women. One of Mr Norris's friends described them as a "militant blue-rinse coven". He said: "Diane Collins was chairman of the association when Steve was the MP. Her husband left her for a younger woman. That really formed her opinion of men like Steven and she had been pursuing a personal vendetta against him."
There was also an unsubstantiated claim that she wanted Epping Forest for her son, Tim Collins - a spin-doctor to the former prime minister Mr Major - before he was selected for the safe country seat of Westmorland and Lonsdale in Cumbria. Neither Mr Collins nor his mother was available for comment last night.
The letter highlighting Mr Norris's alleged misdeeds was sent to all chairmen of Tory associations in London and later discussed at the meeting.
One of those who was present said that it did a "comprehensive demolition job" on Mr Norris's private life and his political record.
Having been left with egg on their faces over the way they had approved the candidacy of Lord Archer of Weston-super-Mare, the letter addressed their doubts about Mr Norris, who had been the front-runner once Lord Archer was out of the field. "The mood was one of apprehension. People were frightened that what had happened over Archer could happen over Norris. He was far and away the best candidate, but the nagging doubts would not go away," the party chairman said.Reuse content