Roseanna Cunningham, the SNP's environment spokeswoman, who almost won the Tory-held rural seat at the general election, was forced to withdraw her application to stand next month after being accused of having an affair with the then husband of Margaret Ewing, the SNP's parliamentary leader.
The accusation was made by Winnie Ewing, the nationalist MEP who is Margaret Ewing's mother-in-law. Challenged at an official party selection meeting, Miss Cunningham admitted having had a relationship with Donald Bain, a former SNP researcher, while he was married to Mrs Ewing.
She denied she had helped to break up the eight-year marriage, telling party officials the affair began after the couple separated more than 10 years ago. But in a statement yesterday, Miss Cunningham said that she had abandoned her candidacy "with great regret".
Winnie Ewing's intervention has strengthened the suspicion that SNP leaders were determined to ensure Miss Cunningham did not stand. Privately, senior officials have expressed concern that her well-known left-wing, republican views would hamper party chances.
Alex Salmond, SNP leader, said yesterday that he "appreciated" Miss Cunningham's reasons for withdrawal. Winnie Ewing refused to discuss her intervention. Margaret Ewing, now married to Winnie Ewing's son Fergus, rebuffed her mother-in-law, saying "foolish, prurient...stories" about her private life were "of no present relevance". There was no animosity between her and Miss Cunningham.
The SNP candidate to fight the seat will be chosen by the Perth and Kinross constituency association next week. Alasdair Morgan, a right-winger and former SNP deputy leader, is believed to be the front-runner.Reuse content