Former prime minister and Progressive Conservative leader Brian Mulroney gave a ringing endorsement to Conservative Leader Erin O'Toole Wednesday evening.

At a Conservative rally at the Hôtel Chéribourg in Orford, Que., Mulroney praised O'Toole's leadership of the party, calling him "steady, strong and visionary."

O'Toole's campaign appearance alongside an former Progressive Conservative leader like Mulroney is another sign that the Conservative leader is making a play for more moderate voters.

Earlier Wednesday, O'Toole tried to distance himself from the policies of past leaders like Stephen Harper and Andrew Scheer, who were more closely tied to the Conservative party's other predecessor parties — the more right-wing Reform and Canadian Alliance. Under Harper and Scheer, some past PC supporters felt alienated from the Conservative cause and defected to the Liberal party.

"My priority has been to build a Conservative movement where every Canadian can feel at home. Inclusive, diverse, forward-looking, progressive, worker-friendly," O'Toole said at a campaign stop in Saguenay, Que. "We're not your dad's Conservative Party anymore."

Referring to his own tumultuous time in office, Mulroney suggested that in a post-COVID era, an O'Toole-led government might have to make some major changes that could prove divisive.

Mulroney left office deeply unpopular with voters. In retirement, he has worked to rebrand his failed constitutional reform efforts and his introduction of the Goods and Services Tax (GST) as initiatives that were necessary to country's continued prosperity.

"There'll be tough and deep structural changes to be made for our country if we are to enhance the prosperity and influence of Canada," Mulroney said.

"Some of these decisions may make Erin unpopular. Of course, I never was ... Canadians are very resistant to change but I know that he and his government will persist and implement their agenda and will be looked upon then and throughout history with favour."

Mulroney's campaign appearance happened just a day after former Liberal prime minister Jean Chrétien spoke at a party rally in Brampton, Ont., in support of Liberal Leader Justin Trudeau.

WATCH / Former PM Mulroney endorses O'Toole

Unlike Chrétien, Mulroney did not criticize the leaders of rival parties in his speech.

"I'm not here tonight to attack anybody. I'm here for one single reason — to help elect Erin O'Toole as the next prime minister of Canada," Mulroney said to cheers.

Mulroney also drew attention to similarities between himself and O'Toole.

"I married up, and so did Erin," Mulroney said, referring to his spouse, Mila, and O'Toole's, Rebecca. "I became a lawyer, so did Erin."

When O'Toole took the stage, he took shots at Trudeau over calling a mid-pandemic election and Liberal scandals involving SNC-Lavalin and the WE Charity.

"We're in the very last stretch of the race, and this is when we're kicking it into high gear," O'Toole said. "The one reason why Mr. Trudeau has called this election is to save his job."

Mulroney, who is 82 and was prime minister from 1984 to 1993, generally has stayed away from campaign events in federal elections since leaving politics. He was the last Progressive Conservative prime minister elected with a majority government; in 1984 his party won the largest number of seats at the federal level in Canadian history.

Mulroney retired in 1993 and under his successor, Kim Campbell, the PCs lost all but two of their seats in the 1993 federal election.

In his speech, Mulroney said that O'Toole spoke with him in the months leading up to the election.

"I had a call from Erin. He said, 'Prime minister, I should tell you that there are bad polls, predicting my defeat. We are getting negative media coverage, and there is grumbling in the party. What do you think?'" Mulroney recounted.

"'I said, 'Erin, I think you should be thrilled ... because that's exactly what they said about me, three months before the election in '84 when we won the largest majority in the history of Canada.'"