Former federal cabinet minister Helena Guergis says she will appeal the Conservative Party's decision to drop her as a future nominee in her Ontario riding of Simcoe-Grey.

MP Helena Guergis at the Simcoe-Grey riding association's annual general meeting in New Lowell, Ont., on April 24. (CBC)

In a letter to party executive director Dan Hilton, the sitting MP asks what she has done to justify the "drastic measure," which she says "defies the wishes of grassroots electors" in the local riding association.

"In recent weeks, in essence, I have been charged, convicted and sentenced without any due process or knowing what I have done wrong," Guergis wrote.

"There have been endless rumours and allegations unfairly levelled against me, but to date I have not been given a specific reason for my removal from caucus, nor has there been any investigation launched, let alone concluded.

"I am confident that I have done nothing wrong and will be exonerated of all the baseless accusations in the media."

Guergis is sitting as an Independent MP after she resigned her junior cabinet post and Prime Minister Stephen Harper kicked her out of the Conservative caucus on April 9 following allegations about her conduct. Harper forwarded the matter to the RCMP, as well as the federal ethics and lobbying commissioners.

She and her husband, Rahim Jaffer, a former Conservative MP, are disputing allegations that include illegal lobbying and conflict of interest.

Speaking to reporters in the Netherlands in Thursday, the prime minister deflected questions on the decision to remove Guergis as a Tory candidate, saying he doesn't "typically comment on party matters."

"In terms of the other issue and nominations, the party makes the decision about the nominations," Harper said. "A party spokesman can reply on those things."

The Conservative Party would not offer comment on the story.

The move against Guergis comes less than two weeks after she received the backing of the riding association at its annual general meeting.

Guergis's status was not discussed at the meeting, Andy Beaudoin, the association's outgoing secretary, told CBC News, adding that many at the meeting — "if not all" — would remain loyal to her.

"She is still the riding's Conservative candidate and people want it to stay that way," he said after the meeting.

Complaints of party interference

At that time, riding officials also accused the Conservative Party of using heavy-handed tactics to replace Guergis with well-known Conservative activist Kellie Leitch, an orthopedic surgeon at the Hospital for Sick Children in Toronto and director of the Health Sector MBA program at the University of Western Ontario's Richard Ivey School of Business.

No federal election is in the immediate future as the Conservatives continue to run a minority government.

In a lengthy letter to Harper, the Conservative electoral district association in Simcoe-Grey complained of repeated interference, obstruction and gag orders by Conservative headquarters.

"We don't want to lose this seat in the next election. But head office personnel have deliberately interfered with, obstructed and circumvented our autonomy as an association and our right to freely express our opinions," the executive members wrote.

The Conservative Party's constitution states its national candidate selection committee "shall have the right to disallow the candidacy of any person before or after nomination by the electoral district association," subject to the appeal of such a decision to the party's national council.

In the case of such an appeal, the national council can decide to issue a "final and binding" ruling, or instead refer the matter to the party's arbitration committee for decision by a panel.

With files from The Canadian Press