MONTREAL -- Canada's aging population is putting more pressure than ever on provincial health-care budgets, Bloc Quebecois Leader Gilles Duceppe said Tuesday, adding that the issue will be a major campaign theme for his party.

Duceppe said his rivals are threatening the long-term financing of the Canada Health Transfer, a federal program that distributes money to provinces to help pay for government-funded medical services.

"Health care is certainly the most important issue in the federal election campaign," Duceppe said in Montreal.

"Most urgently, we need to re-establish the transfers in order to breathe life into the system."

The Conservatives plan to change the health transfer formula once the current funding agreement between Ottawa and the provinces expires in 2017. The party says it would use a new formula that would tie funding increases to economic and population growth, promising the transfers would never fall below three per cent a year.

Duceppe called on the next federal government to consider costs related to the country's aging population when it proposes a new health deal.

He said Quebec would need an extra $7.3 billion over 10 years to cover those aging-related costs.

Liberal Leader Justin Trudeau has said that, if elected, he would work with the provinces to come up with a new long-term health accord.

NDP Leader Tom Mulcair has promised to do the same thing, but his hesitation to reiterate in an electoral context his commitment to cancelling any possible cuts has raised some concerns.

Duceppe said Quebecers cannot trust Mulcair about health funding because of the NDP's promise to balance its first budget.

The parliamentary budget officer's 2015 report noted the country's aging population continues to put pressure on health budgets across the country, a problem it said could be solved with more funding.

Catherine Loubier, a spokeswoman for the Conservatives, defended the Tories' record on health funding.

"The health transfers to provinces are the highest in our history and under the Harper government will continue to increase in a way that is foreseeable, maintained and without precedent," she said in an email.