Senior Tory MP Anne McIntosh has lost her battle against de-selection by local Conservatives.
In a statement, the party said that the Thirsk and Malton Conservative Association had voted not to re-adopt her as their candidate for the next general election.
Miss McIntosh, who has been an MP since 1997, immediately announced that she intended to stand as an independent in the seat which she held at the last election with an 11,281 majority.
Speaking outside Conservative HQ in London where the votes were counted, a defiant Miss McIntosh said: "I do not intend to be thrown aside by a small group.
"It is for my constituents as a whole to dismiss me if they wish to do so."
Miss McIntosh, who has enjoyed a high profile in recent weeks as the chairman of the Commons Environment Committee dealing with the fall-out from the floods, added: "It is my intention to stand for Thirsk, Malton and Filey constituency at the next general election.
"Meanwhile, I remain committed to the Conservative Party locally and nationally and shall continue with my constituency and parliamentary duties with my customary passion.
"In the coming year I will support Conservative candidates in the European elections in Yorkshire and the Humber and Conservative local government candidates in Thirsk, Malton and Filey in 2015."
The vote follows a bitter internal battle in the local party where she was said to have fallen out with the executive - in particular its chairman, Peter Steveney, a retired Army major and former Jockey Club stewards' secretary.
An internal Conservative Party report found that a previous vote to de-select her had been "fundamentally flawed" and ordered that the result should be set aside.
The local party was said to be "troubled by factions" while the executive was found to have broken the rules by co-opting a large number of new members on to the association's executive board weeks before the ballot was held.
Labour frontbencher Jon Ashworth said the result was a further blow to the Tories following announcements by a series of Conservative women MPs that they did not intend to stand again at the next election.
"What on earth is the Conservative Party's problem with women? With Anne McIntosh deselected, the Tories look set to lose their only female MP in the whole of Yorkshire and the Humber," he said.
"Already one in 10 of the Conservative women MPs elected in 2010 have announced that they are standing down at the next election. David Cameron has done nothing to stand up for one of his most senior women MPs.
"His silence speaks volumes at a time when many people are asking why the Conservative Party is so out of touch."