Stephen Harper broke his lengthy public silence Thursday night to bid farewell to the Conservative Party he created and led for more than 11 years, delivering what amounted to a motivational speech for a political organization still adjusting to life on the opposition benches and uncertain on what it might take to unseat Justin Trudeau.

He avoided taking shots at the Liberal Prime Minister, except to predict that by 2019, when the next federal election will likely be held, "perhaps more than we understand even now, our country will need a strong, united Conservative Party" ready to govern.

"I don't plan to spend long on this stage tonight," Mr. Harper told the Conservative convention in Vancouver Thursday night. "I've come to quite enjoy being off centre stage," he joked to a room where the crowd exceeded 2,300.

Story continues below advertisement

Mr. Harper, as The Globe and Mail first reported, intends to resign his Commons seat by the fall.

The former Tory leader made much of the fact the Tories, even in defeat, managed to end the 2015 election with 99 seats – far better than electoral wipeouts suffered by the Liberals or the former Progressive Conservative Party after stretches in power.

He lauded his successor, interim Conservative Leader Rona Ambrose, saying that "in a short time [she] has become one of the most effective opposition leaders the country has ever seen."

The speech was clearly directed at Mr. Harper's Conservative tribe rather than Canadians at large, with the ex-leader dedicating much of the 1,849-word address to a succession of people within Tory ranks from fundraising officials to his former Prime Minister's Office staff.

Mr. Harper's effort to sum up his political record recalled the familiar patter of his 2015 campaign speeches.

"It was thanks to you that we were able to cut taxes to their lowest level in 50 years and put dollars back into the pockets of families … to get tough on crime, to rebuild our military, to vastly expand Canada's global free-trade access [and] to witness the decline of Quebec separatism and Western alienation," he said.

"And to stand up as a country and take principled positions in a dangerous world."

Story continues below advertisement

Conservative Party organizers said the publicity-shy Mr. Harper, who has kept a remarkably low profile since his electoral defeat last October, had to be prodded to even deliver this short address at its Vancouver convention, which runs until Saturday.

The 57-year-old MP was not expected to linger after the send-off at the Vancouver gathering, where more than 2,100 Conservative delegates are trying to reboot and revamp a party that has only had one single leader – Mr. Harper – since it was founded in 2003.

"We had to twist his arm to even get him here," one Conservative Party organizer, who spoke on condition of anonymity, said Thursday.

A protracted battle over the direction and leadership of the party lies ahead with a leadership vote scheduled one year from now in May, 2017.

The list of declared candidates to replace Mr. Harper is still short. Potential contenders with big name recognition and clout, such as former justice minister and co-founder of the Conservative Party, Peter MacKay, and former defence minister, Jason Kenney, remain undecided as Tories mull over their chances of defeating Mr. Trudeau in the next federal election.

Mr. Kenney said Thursday he would support an effort to let the interim leader Ms. Ambrose run for the permanent leadership. "I think she has been a fantastic deputy leader," he said. "I think she would be a phenomenally strong permanent leader."

Story continues below advertisement

He also announced that he would make his own decision sometime this summer on whether to run for the helm. Mr. Kenney said he would weigh the time commitment. "I have been in Parliament for 19 years and whoever steps forward for this leadership has to put in probably a decade or more."

The party is also wrestling over whether to jettison some of its socially conservative policies including its disavowal of gay marriage and an aversion to euthanasia. Other proposed policy changes include directing police to issue tickets rather than charges for possession of small amounts of marijuana.

Saskatchewan Conservative MP Tom Lukiwski, who's taking part in the Vancouver convention, said "likeability" is a key asset for the next leader. "If Stephen Harper had the likeability factor of say, Brad Wall, we would have won the last election," he said, referring to the current Saskatchewan premier. Mr. Lukiwski said, however, he believes Mr. Wall when the provincial leader says he won't run to replace Mr. Harper.