A former journalist at the National Post has withdrawn from the race to carry the banner of the Conservative Party in an area of Toronto, saying she has "clear evidence of a corrupt process."

In a social media post on Thursday, Sabrina Madou announced she has suspended her party nomination race in Aurora, Oak Ridges, Richmond Hill. She stated that she had been a "clear target of extremely unethical, and possibly illegal, efforts to influence the vote" because another candidate had a party membership list before her.

She said: "Unfortunately, I no longer trust the integrity of the election," "I call on the Conservative Party of Canada to secure our democratic nomination process, uphold our values, and stand against corrupt campaigns that show contempt for both."

Madou did not name the alleged candidate who had the membership list.

She suggested that a mass email sent to party members during the election campaign criticizing her nomination was evidence that someone unfairly gained access to the names and contact details of party members in violation of party rules, and CBC News did not review this email.

The Conservatives describe these allegations as "completely false."

A party spokesperson told CBC News that Madou's claims and membership list allegations are "completely false."

Sarah Fisher stated: "It is common for the party to receive complaints from nomination candidates about their opponents due to suspicions of misconduct and the use of lists."

"In fact, we received a complaint regarding Ms. Madou's campaign emailing current and former party members when she was not supposed to be able to access the membership list."

Conservative sources who spoke to CBC News on condition of anonymity said that Madou sold only about 50 memberships in the nomination race—a low number that likely means she had little chance of winning the nomination.

When asked about the claim regarding her membership sales, Madou said: "That’s not the case." "We certainly sold more than 50 memberships, and she did not give an accurate number."

Madou said she is not speaking now because she was about to lose. She said she would have quietly accepted losing a contest she considered fair, "this is not how I wanted things to go," "it's very difficult and heartbreaking."

When asked whether she still supports party leader Pierre Poilievre, Madou said she was inspired to run by the leader's "vision for change."

She said: "I still want to support him as the leader, but it seems there are still some issues within the party apparatus."

Madou was in a tough battle for the York nomination against former MP Costas Menegakis, who held the seat from 2011 until the party's defeat in the 2015 election.

He ran again in 2019 and 2021 in neighboring Richmond Hill and lost both times to a Liberal, which Madou highlighted in a previous interview as a reason for choosing to run instead.

Madou presented herself as a "new conservative voice," while Menegakis told True North earlier this year that he is "experienced in leadership," while Madou is a political novice.

The race they both competed to represent was conducted by the Conservative Party in 2019, indicating it is a seat that can be won by the party, given how well the Conservatives have performed in national polling.

The party's membership list is an important document that is distributed to potential party candidates; it is what candidates use to focus their campaigns on members they expect to vote, thus saving campaign time and resources.

Madou said: "If one campaign has this list and other campaigns do not, then the nomination is effectively being rigged in its favor, every day with an official list is like a campaign for weeks without a list, that's how important it is."

Under the Conservative Party rules, the membership list cannot be provided to nomination candidates until the "final notice" is issued, when the door to nominations for other potential party candidates is closed.

However, the party's membership list, which exists in the foundational information management system, has been widely used in election cycles in recent years, when the party held three national leadership campaigns and dozens of nomination meetings for four general elections.

Madou claims "a smear campaign."

Madou said she has evidence suggesting that another unnamed candidate had a list—including personal contact details of party members—prior to the "final notice" and used it to circulate damaging details about her to undermine her chances of winning.

She said, "A mass email was sent to an updated version of the official membership list that no candidate was permitted to have until now, and no one was given the green light."

Madou said the email, supposedly written by someone named Norman McDaniel, served as a "smear campaign."

The email to party members confirmed that the community "deserves better."

The email read, according to Madou: "This is a candidate who does not share our values and will embarrass us if she reaches Parliament." The party confirmed that there is no Norman McDaniel in the race, Madou said.

Madou said she asked the party to investigate two weeks ago but was dissatisfied with their response to her concerns.

Fisher confirmed that the party "received a complaint from her campaign regarding the emails distributed to members highlighting things Ms. Madou has written and said in the past."

The Conservatives have faced at least two other allegations that party leaders preferred one candidate over another in the nomination race.

Last year in Oxford, a riding in southwestern Ontario, Arpan Khanna received the endorsement of the daughter of the outgoing MP.

This prompted allegations that Khanna, who previously ran in Brampton, Ontario, and worked as a co-chair of Poilievre's leadership campaign, was a parachute candidate who unfairly displaced a local leader and anti-abortion activist.

The party insisted that the race was fair and that Khanna easily won the most votes in the nomination.

Khanna went on to win the federal by-election, but by a margin closer than some expected in the strong Conservative race.

Earlier this year, local Conservatives also raised concerns about the party allegedly favoring the former Ontario Conservative MP, Parm Gill, to run in Milton, Ontario, according to a report in The Hill Times.

Disputes over a political party allegedly favoring one candidate over another are not unusual. The Liberals have faced similar claims in the past.

In 2015, Ottawa lawyer David Bertschi filed a lawsuit against three senior officials of the Liberal campaign after withdrawing his approval to carry the Liberal banner.

After Bertschi exited the race, former Canadian Forces general Andrew Leslie was hailed as the candidate in Ottawa-Orléans.