A former Tory cabinet minister will be feted at a cocktail fundraiser Tuesday, informally kicking off what is expected to be a long and costly Conservative Party leadership race.

CBC News has obtained an email copy of an invitation to an event to drum up funds and support for Kellie Leitch, a pediatric surgeon and the former minister of labour and status of women who is expected to mount a leadership bid.

According to the email, the event at Edmonton's Royal Glenora Club offers a chance to hear from the Ontario MP about why "she is the best candidate to lead the Conservative Party of Canada into the next election." It also delivers a reminder that donors can give up to $1,525 each calendar year for the cause.

CBC News has also learned that Quebec MP Maxime Bernier will file his candidacy papers this week, and formally launch his leadership bid at an event in Quebec City later this month. Bernier, who plans to frame his campaign around lean government and ending subsidies for business, has been meeting with party supporters across the country for months now.

The organizer for the Leitch event declined to comment on the "private" event, and a call to Leitch was not returned.

Former Conservative cabinet ministers Kellie Leitch and Maxime Bernier are both laying the groundwork to launch leadership bids to replace Stephen Harper. (Canadian Press)

The email describes Leitch as a "tireless worker and dedicated Conservative."

"She campaigned for 70 different candidates in the most recent federal election; candidates from coast to coast. She did this because she cares about Canada and she believes strongly that the Conservative Party of Canada offers Canadians the best opportunities to lead happy, safe and successful lives," it reads.

Leitch was also involved in last fall's controversial campaign event to announce a new RCMP tip line for so-called "barbaric cultural practices." The move was widely panned, with some criticism coming from within the Conservative ranks.

No registered candidates

Donations are to be paid to the Conservative Fund Canada with a "reference" to the Kellie Leitch campaign. The note says MPs and community leaders will be in attendance.

The party's leadership convention will be held May 27, 2017.

Other possible candidates include former cabinet ministers Tony Clement, Jason Kenney and Lisa Raitt, along with businessman and television personality Kevin O'Leary.

Peter MacKay has not ruled out a run for the Conservative Party leadership, and some polls point to him as a potential front-runner. (Andrew Vaughan/Canadian Press)

Early polls suggest former cabinet minister and ex-leader of the Progressive Conservative Party Peter MacKay could be a front-runner if he enters the race.

So far, he has only said he hasn't ruled out a leadership run.

The spending cap has been set at $5 million, which is more than five times the $950,000 limit for the 2013 Liberal leadership campaign. The NDP had limit of $500,000 in 2012.

Must be card-carrying Tories

The Liberal campaign was five months long, and the NDP race was six months.

Candidates must be card-carrying Conservative members for at least six months before they can enter the race.

The Conservative caucus picked Rona Ambrose to serve as leader on an interim basis with the understanding she would not seek the job permanently.

Candidates must register by Feb. 24, 2017.