Sue Catling fought the Calder Valley seat in 2001

Sue Catling, 43, had been the prospective candidate since 1999, but on Monday night was deselected by the Calder Valley Conservative Association.

Opponents within the local party have claimed she was guilty of misconduct.

But Mrs Catling denied the allegations, claiming she had been the victim of a "dirty tricks campaign".

I will still vote Conservative, but this is the end of my candidacy in the Conservative Party - I want nothing more to do with it Sue Catling, ousted candidate

She had survived two previous attempts by the party to deselect her over unspecified allegations, but was voted out at the third attempt during meeting in Lightcliffe, near Halifax.

Mrs Catling said: "I feel pretty miserable. I have given five years to the party and did not deserve this.

"They [the local party] orchestrated the most sustained campaign of dirty tricks any candidate has had to put up with anywhere in the country and have been allowed to get away with it."

'Strong contender'

Mrs Catling, originally from Cheshire, said her treatment gave the impression that the Conservative Party was "utterly dysfunctional from the top to the bottom".

"Why would they let this happen to a candidate who, as you [the media] will know was ranked very highly at the last general election?"

The BBC's political editor in Yorkshire, Len Tingle, said that on paper Mrs Catling was an excellent candidate.

In 2001, she lost to Labour's Christine McCafferty, but halved the deficit to 3,094.

Mrs Catling said she would not be seeking election elsewhere.

"I will be a Conservative until I die. I will still vote Conservative, but this is the end of my candidacy in the Conservative Party - I want nothing more to do with it."

The Calder Valley Conservative Association has been unavailable for comment.