Ex-columnist Sabrina Maddeaux, once touted as rising Conservative ...

Sabrina Maddeaux says the race was tipped in favour of an unnamed candidate.Ryan Emberley/The Globe and Mail

A former political columnist who has been a high-profile voice in the Conservative Party has dropped out of a nomination race, alleging “a corrupted process.” The party says her claims are “completely false.”

Sabrina Maddeaux left her column at the National Post in January to run for the Conservative nomination in the Ontario riding of Aurora-Oak Ridges-Richmond Hill. The nomination race includes former MP Costas Menegakis and is highly coveted because it’s widely believed the Conservatives would win it back from the Liberals in the next election.

In a lengthy social-media post Thursday, Ms. Maddeaux said the race was tipped in favour of an unnamed candidate who she believes had access to membership lists that no campaign was supposed to have. She said an unknown person, falsely claiming to be a Conservative in the riding, used the list to send two e-mails to local party members that were “full of defamatory smear attacks and deliberate misinformation.”

One of the e-mails included quotes and links to her past columns and articles dating back more than a decade, ranging from a critique of former Conservative prime minister Stephen Harper’s record to getting a pride flag painted below her panty line.

Ms. Maddeaux said in an interview that sections of the e-mails included “outright lies” and none of the articles referenced amounted to a scandal. She also argued that ones dating back more than a decade “shouldn’t be relevant to running a campaign.”

The e-mails were sent two weeks ago. She said her campaign asked the party to investigate and send its own e-mail notifying members that the e-mail was not from a local party member. However, she said she’s received no updates from the party and so decided to leave the race.

“Without action by the Party, the democratic process has been irrevocably corrupted and rigged in one candidates’ favour,” she said in her social-media post.

Conservative Party spokesperson Sarah Fischer said in a statement to The Globe and Mail that Ms. Maddeaux’s campaign also sent e-mails using membership lists she should not have had access to.

“The allegations Sabrina Maddeaux made are completely false,” Ms. Fischer said. “It’s common for the Party to receive complaints from nomination candidates about their competitors over suspicions of wrongdoing and the use of lists.”

She did not reply to a query about whether the party ever investigated the complaints.

Two Conservative Party sources said Ms. Maddeaux was leaving the race after only signing up about 50 new members. They said the number was very low, especially in a hotly contested race, and likely would have led to a loss.

The Globe is not identifying the sources because they were not permitted to disclose the internal information.

Ms. Maddeaux disputed the number and told The Globe her campaign had signed up more than 200 members and identified more than 1,100 supporters.

The party has not yet announced a date for the nomination vote.

With reports from Laura Stone and Ian Bailey