As global stock markets plunged on Monday, Conservative Leader Stephen Harper urged voters to stick with his party's fiscal plan, while NDP Leader Tom Mulcair and Liberal Leader Justin Trudeau said a change in government would boost the economy.

The S&P/TSX composite ended the day down 421 points while the Dow Jones industrial average lost 588 points. The loonie closed at its lowest level since August 2004, hitting 75.4 cents U.S.

Speaking in Quebec, Harper acknowledged that Canada is facing "economic challenges," but pointed to the Conservative record of investing in innovation, infrastructure, immigration, training, and trade to create economic growth.

"We're making investments in the things that will get us through this, and position us well for the long term," he said.

He also highlighted Canada's "disciplined" financial framework, including a strong banking system, a balanced budget, and low taxes.

By contrast, Harper said, the NDP and Liberal Party are proposing large-scale permanent spending increases, which they would finance through deficits and tax increases.

"We think that is clearly the wrong track. It would be clearly damaging both in the short term and the longer term in this country," he said. "Given the challenges around us, we need to stick with a long-term plan that has been working and will work."

Harper’s office released a short statement Monday stating that he had spoken on the phone in the morning with Bank of Canada Governor Stephen Poloz.

"Prime Minister Harper and Governor Poloz discussed the recent decline in global stock markets and commodity prices, slowing growth in China and emerging markets and the potential impacts on Canada's economy,” the statement read.

Market researchers at CIBC, meanwhile, offered a delicate warning to investors.

The bank’s latest institutional equity research paper states that the “Canadian situation is complicated by a lack of domestic support for Canadian equities, continued pressure on the economy from weaker commodity prices and a Federal election that could result in a party other than the Conservatives or Liberals in power."

One of the paper’s authors, Ian de Verteuil, later said the statement wasn't a critique of any party's capabilities or policies.

"This is a comment on how investors tend to have a short-term reaction to change,” he told The Canadian Press in an e-mail.

“Election uncertainty may be a factor in equity markets but far more significant issues are weak commodity prices and low demand for Canadian equities.”

Real risk is sticking with the ‘status quo’: Trudeau

Speaking at a campaign event in Belleville, Ont., Liberal Leader Justin Trudeau said the Conservative government’s benefits and tax breaks for the wealthiest Canadians have failed to create the kind of "economic growth we need."

The Liberals, he said, will instead invest in measures that support the middle class.

"It's time that Canadians have confidence in the economy as they look to the future, and not face a government that has no plan and wants you to think that sticking with what we have is well enough," Trudeau said. "The real risk is not making a real change from the failing status quo."

The Liberal leader acknowledged Canada’s economy is subject to such global forces as low oil prices, but said a federal government must look for new ways to address these challenges.

Trudeau said the Liberals will grow the economy by investing in people, rather than the Conservative plan of "desperately hoping oil prices will bounce back up."

Asked about how falling oil prices might affect the budget, Trudeau said, "We have to recognize that Stephen Harper has put us into deficit.”

Mulcair: NDP will raise tax rates on large corporations

Meanwhile in Toronto, NDP Leader Thomas Mulcair said that if elected, the New Democrats will "kickstart" the economy by investing in infrastructure, transit, and housing.

He also said the NDP will champion manufacturing, tourism, and green technologies.

"We have lost 400,000 good paying jobs in the manufacturing sector," Mulcair said.

Mulcair added that Harper has "put all his eggs in one basket" by focusing the Canadian economy on the oil and gas sector.

Mulcair highlighted the New Democrat pledge to reduce tax rates for small business from 11 per cent to nine per cent, which he says will encourage the hiring of more workers.

Mulcair accused Harper and Trudeau of supporting tax reductions for large corporations, which the NDP oppose.

"We're saying clearly that Canada's largest corporations are the only Canadians not paying their fair share, and we will be raising their rate," he said.

Mulcair defended the NDP promise to create a $15-a-day childcare program, which has come under attack by Trudeau and Harper as being economically unfeasible.

Analysts say the daycare plan will help families and will also allow more women to remain in the workforce after giving birth, which ultimately benefits the economy, Mulcair said.

Global worries driving Canadian concern

TD Bank’s Deputy Chief Economist Derek Burleton told CTV’s Power Play on Monday that unlike the 2008 financial crisis, the recent economic woes stem from China and other emerging markets.

“It’s really the main source of headwinds, particularly China -- the focus on dramatically slowing growth there,” said Burleton.

Despite low prices, Burleton said Canadians don’t need to start stuffing their mattresses with cash just yet. Since the U.S. market is “relatively immune,” he said Canada stands to benefit from that stabilityas it’s number one trading partner.

“My view is the U.S., doing quite well, is going to provide some benefit to the Canadian economy in general.”

Burleton cautioned against calling for stimulus at this point.

“Clearly, if the Canadian economy doesn’t improve, then significant stimulus is something that could be looked at, along with further interest rate relief by the Bank of Canada. But in terms of responding to the recent few days … it’s a little bit quick.”

With files from The Canadian Press