Stephen Harper used what could be his last convention speech before an election to assure grassroots Conservatives that he's still an outsider fighting elites in Ottawa despite more than seven years in power and a turbulent Senate expenses scandal.

In a 3,900-word address to thousands of rank-and-file Tories at the Calgary gathering, the Prime Minister painted himself as the only federal politician that can be trusted to fight for ordinary Canadians, building on his party's sense of itself as interlopers in the nation's capital.

"We didn't go to Ottawa to join private clubs or become part of some elite," said Mr. Harper, whose party has been stung by accusations that Tory Senate appointees padded their expense claims.

Story continues below advertisement

"Ours is not the party of entitlement, not guided by power or privilege … and we never should be."

He also assured Tories, who frequently applauded his speech, that current troubles will pass if they stay focused.

"So, friends, work hard on the things that matter … deal with problems as they arise," Mr. Harper told the crowd.

"And Canadians will understand in the next election that … the only choice to keep our country on the right track is the Conservative Party of Canada."

He said the Canadians his party fights for include "unsung heroes" such as "the cab drivers, the small business owners, the farmers … office workers."

Tories privately say they are fighting complacency and malaise in the countdown to the next election in part because of the Senate scandal – a development that has damaged the government's self-cultivated image as reformers.

Speaking to the crowd, Mr. Harper sought to rebuild his Main Street credentials by celebrating his push to suspend without pay Mike Duffy, Pamela Wallin and Patrick Brazeau even though the senators have not been charged or found guilty of anything.

Story continues below advertisement

He told the crowd "he couldn't care less" what critics – a group that includes members of his own caucus – think of the move to turf the senators.

"Every week I face demand from our opponents that we immediately fire or expel people – often on the flimsiest of allegations," Mr. Harper said.

"Then, when we decide that a case, based on the facts, requires serious sanction, our opponents immediately accuse of us of being unfair, nasty and ruthless – and they then portray the offenders as victims or even martyrs."

Even among staunch Conservative MPs, there's a concern the government doesn't have more signature accomplishments to show for winning a majority two years ago.

Mr. Harper went to great efforts in the speech to highlight his achievements, not only over the last two years but over his entire tenure in government. He reminded Tories of the tax cuts, tough-on-crime bills, the drive to balance the budget by 2015 and the recent Canada-European Union trade deal.

"A typical family of four pays more than $3,000 less in taxes than when we came to office: that's car payments for a year," the Prime Minister noted.

Story continues below advertisement

"When we say 'vision,' we don't mean some ivory tower theory," Mr. Harper said. "That's what passes for vision among elites in Ottawa."

He reached all the way back to 2006 to remind the partisan crowd of how the Conservatives cancelled the former Liberal government's state-funded childcare plan and instead created a new cash benefit for parents.

"We took the money out of the hands of the lobbyists, academics and bureaucrats and we gave it to the real childcare experts: their names are Mom and Dad," Mr. Harper said.

He took well-practised swipes at his political rivals, using lines he's been fine-tuning over the summer in smaller speeches to Conservative supporters.

The Prime Minister dismissed Liberal Leader Justin Trudeau as a lightweight and reminded the crowd of his rival's pledge to legalize marijuana.

"In 2015, we're not choosing the winner of Canadian Idol, we're choosing someone to lead our economy," Mr. Harper said.

Story continues below advertisement

"The only trade policy Justin Trudeau's been working on is the marijuana trade."

Mr. Harper needs to re-energize the Conservative grassroots who will run the Tory election machine in 2015.

The Conservative Party of Canada generally holds a convention every two years but officials say it's very possible a 2015 gathering might be delayed or cancelled because of a federal election.