The day before MPs return to the House of Commons, Prime Minister Stephen Harper set the tone in the run-up to the 2015 election with a campaign-style rally just outside Ottawa.

Harper addressed a high school gym packed with hundreds of supporters in Orleans, Ont, on Sunday, just nine months before the tentatively scheduled federal election.

When MPs return to work Monday, opposition parties are expected to grill the prime minister on an uncertain economy and the war against the Islamic State.

But Harper continued to push his firm stance on security issues during Sunday’s speech. He promised to introduce legislation on Friday that ensures "police and security forces have the tools they need to meet evolving threats and to keep Canadians safe."

The legislation is expected to give law enforcement new sweeping powers to detain suspects, track weapons and to restrict the movements of suspected extremists by making it easier to prevent them from boarding planes and lowering the threshold for obtaining a peace bond.

Changes to the country's anti-terror laws were promised in the aftermath of the deadly attacks on Canadian soldiers last October on Parliament Hill and in Quebec.

Harper's hardline stance on terror, as well as his decision to join a coalition air campaign against ISIS in Iraq have paralleled a boost in popularity for his Conservative party. The Tories and Liberals remain close in recent polls, with the Official Opposition NDP trailing in third.

While Harper says the new legislation will not infringe on civil liberties, opposition parties are concerned.

"You can't protect freedoms while destroying those very same freedoms," NDP finance critic Nathan Cullen told the Canadian Press.

Plunging oil prices

In the coming months, opposition parties also plan to raise questions on an issue that in the past has been a cornerstone of the Conservatives’ election campaigns – economic policy.

"The government has a serious set of very troubling economic issues to deal with and they're sending a message of confusion and incompetence in addressing those issues," Liberal Deputy Leader Ralph Goodale told The Canadian Press.

The Conservatives will be forced to confront the shock of plunging oils prices – current prices stand around $50 a barrel, down from more than $100 a barrel in June.

The Bank of Canada reacted to the so called "oil shock" on Wednesday by lowering Canada's trendsetting interest rate from one per cent to 0.75 per cent.

The change aims to buffer the Canadian economy from potential damage inflicted by low oil prices.

The bank's governor, Stephen Poloz, said the drop in prices will "reduce the income flowing into Canada and lead probably to some increase in unemployment overall,"

Liberal MP Chrystia Freeland questioned the Conservatives approach to economy. She believes the Harper government has grown too dependent on oil prices.

"They had a single plan, that plan was a 100 per cent focus on oil, and now the price of oil has fallen," Freeland told CTV News.

On Sunday, Harper was steadfast in his intention to deliver a balanced budget and to go forward with the promised income-splitting tax breaks for families with children under 18. This comes despite news that federal coffers could stand to lose $5 billion and Finance Minister Joe Oliver's decision to delay the budget until at least April.

But Harper tried to downplay criticism from opposition parties regarding the economy.

"The government's fiscal flexibility has been reduced, at least for the short term," Harper said on Sunday. "To some, it's a reason not to balance the budget. But to them, there is always a reason not to balance the budget."

Cullen says the NDP will continue to push back against the Conservatives' direction for the economy.

"We will be continuing to put forward ideas, and push back against the really bad choices the government is making like income splitting -- that only helps 15 per cent of the wealthiest Canadians," he said.

October election

An election is scheduled for October 19, but Harper’s majority government could send voters to the polls before then.

Opposition parties believe he could call for an election sooner in order to avoid the potential blowback from the trial of disgraced Tory senator Mike Duffy, which is scheduled to begin on April 7.

The campaign season will continue to ramp up on with Liberal Leader Justin Trudeau expected to critique the government's economic policies at a rally on Monday evening.

NDP leader Tom Mulcair is also expected to offer his assessment in a major speech on Tuesday.

With a report from CTV's Ottawa's Katie Simpson and files from The Canadian Press.