As Alberta businessman Rick Peterson formally announced his bid for the Conservative Party leadership today, sources said some prominent former Conservative cabinet ministers — including John Baird — are being pressured to jump into the race themselves.

Peterson launched his official campaign at High Arctic Energy Services, an oilfield services company near Edmonton.

"Let's put Canada at the forefront of change and innovation and growth and prosperity and potential," he said. "Canada should be a place where the top entrepreneurs all over the world come to make their home."

Peterson is the first Western Canadian candidate and is fluently bilingual. He finished 12th out of 14 candidates in the 2017 leadership race, with less than 1 per cent of the vote.

After early speculation about a large slate of candidates, the Conservative leadership field has dwindled in recent weeks.

A push for more candidates

Former Quebec premier Jean Charest, Ontario MP Pierre Poilievre and former interim Conservative leader Rona Ambrose were all spoken of as likely candidates — until they ruled themselves out of the race. Now, some Conservatives are trying to convince prominent party members to run.

"There is no doubt that there are calls going out across Canada from Conservatives to convince people to either consider or reconsider their positions," said Conservative strategist Jason Lietaer.

John Baird announces his resignation as a member of Parliament on Feb. 3, 2015. (Adrian Wyld/Canadian Press)

A lot of those calls are going to former Harper cabinet minister John Baird, who reportedly was working on Poilievre's own campaign team until Poilievre dropped out. Baird also authored a lessons-learned report on the Conservative Party's performance in the last federal election; that report has not been released.

Baird the 'game-changer'

"Mr. Baird is 100 per cent taking calls," said Lietaer. "A lot of people are trying to get him to reconsider his decision to not run. I think a lot of people think that he would be a game-changer in the race.

"His record of ... long-standing competence, along with his ability to communicate ... would make him a favourite in the race, and certainly a heavyweight in the race. So a lot of people are calling him, a lot of people are hoping he reconsiders, and we'll see where he ends up."

A source close to Ambrose said people have been contacting her and urging her to rethink her decision to stay out of the race. Last Wednesday, Ambrose posted a video on social media saying she prefers the private sector and living in Alberta.

The source told CBC News that the recent pressure likely won't convince her to change her mind.

A 'spicy, bold vision'

Alberta MP Michelle Rempel Garner said today she's still considering her options.

"This leadership campaign can't be a popularity contest," she said. "I really don't want the ballot question in our leadership campaign to be looking for a saviour. "

Erin O'Toole, left, and Peter MacKay have announced their intention to lead the federal Conservative Party. Michelle Rempel Garner is still thinking about it. (Jonathan Hayward/The Canadian Press, Mike Symington/CBC, Justin Tang/The Canadian Press)

Rempel Garner said she wants the race to open debate within the party on policies to defend human rights — including LGBTQ rights — and to support Western Canada and defend national unity,

"That's what our party needs to offer the Canadian public ... a spicy, bold vision that people can clearly resonate with and that reflects modern Canada," she said.

A 'wide-open' race

Today, New Brunswick MP John Williamson said he's considering a bid to replace outgoing leader Andrew Scheer.

"Well, the race is wide-open and there is room, I believe, for a movement Conservative candidate," Williamson told reporters on his way into the weekly caucus meeting. "And those are the waters I am testing right now, to see if that appetite exists amongst our caucus and our members at large."

Asked by reporters what he meant by a "movement" Conservative, Williamson said, "You can figure that out guys."

Williamson is the former national director of the Canadian Taxpayers Federation. He was a director of communications for former prime minister Stephen Harper and is now a member of Parliament for New Brunswick Southwest.

Conservative sources have said Manitoba MP Candice Bergen has been making calls gauging support for a possible leadership campaign. The National Post reported Wednesday night that she has now ruled out a run.

Ontario MP Michael Chong — who ran in 2017 and made himself an outlier within the party by proposing a tax on carbon emissions — ruled out another run at the leadership Wednesday.

In a media statement, Chong said the next leader has to be someone capable of coming up with a credible plan to meet Canada's international commitments on climate change while holding the party coalition together.

WATCH | What Conservatives want in a new leader:

Even with another candidate entering the Conservative leadership race, some party members say the right candidates haven’t entered the fold. 2:01

"Conservatives need a leader that can unite a diverse group that includes social conservatives, social progressives, libertarians, les bleus and fiscal conservatives. In addition to maintaining unity, the next leader must also broaden the party and appeal to a bigger group of voters," Chong said.

Former cabinet minister Peter MacKay is the only approved candidate so far; the Conservative Leadership Candidate Nomination Committee made it official Tuesday night. MacKay has met all the current requirements for entry — a $25,000 entrance fee and 1,000 signatures collected from party members in at least 30 ridings across seven provinces.

Applications to run filed by two other candidates — Ontario MPs Erin O'Toole and Marilyn Gladu — are still under review by the committee.

The deadline to enter the race is February 27.

Launching his campaign today, Peterson vowed to terminate Bill C-48, the northern B.C. oil tanker ban bill, and rewrite Bill C-69, which overhauls the federal environmental assessment process for major construction projects.

He's also calling eliminating corporate income tax and introducing a flat 15-per-cent personal income tax structure.

He said carbon pricing should not apply to individuals or small businesses but should focus instead on large emitters of greenhouse gases.

He also said he supports a "strong firearms policy" that protects the rights of hunters, farmers and sports shooters.