The Liberals and New Democrats sparred today over the NDP's proposed child-care plan while on the campaign trail.

Liberal candidate John McCallum, the incumbent in Markham-Unionville, called NDP financial policies in general "a mirage," and suggested NDP Leader Tom Mulcair is not being realistic about funding child care.

"The NDP does not tell us that the provincial governments have to put up $3.3 billion per year to make this plan work," McCallum told reporters in Ottawa. "Where are the provinces going to come up with $3.3 billion?

"I come from Ontario," he continued. "Ontario has a significant deficit. Ontario would have to come up with a billion dollars plus per year. Where's Ontario going to get that money? If the provinces don't come up with the money, there won't be child-care spaces."

The high-profile Liberal candidate zeroed in on the NDP plan to create one million new day-care spaces, costing $15 a day, saying it will never happen.

Of the three main party leaders, only Mulcair had campaign events scheduled Saturday. He was in Saint-Jérôme, Que., where he highlighted his party's child-care plan and insisted his party will "get it done."

"Across the country, whether it's boards of trade, or chambers of commerce, or local community groups or families, everybody is happy that the NDP has a clear plan to put in place one million, $15-a-day quality child-care spaces," he said.

"Now, I understand the frustration of the Liberals, because they had 13 years to get it done the last time and they didn't get it done. That's their track record. That's their balance sheet. We're going to get it done," Mulcair said.

McCallum, a former bank economist, also took aim at the Conservatives, saying they are weak on the economy.

He asserted the country's books are already back in the red this year, contrary to Conservative Leader Stephen Harper's insistence, before calling the Oct. 19 election, that the budget will be balanced.

McCallum appeared before reporters alongside Montreal Liberal candidate Marwah Rizqy, a tax policy expert, and Chrystia Freeland, a former journalist and author of books on income inequality.

The trio portrayed the Liberals as "the party of balanced budgets."