Liberal Leader Michael Ignatieff said Tuesday the fine print of the federal budget is key and he won't be drawn into a snap judgment on whether to bring the government down.

Ignatieff said he and his advisers will spend Tuesday evening studying the budget document before announcing whether the Liberals will support it during a news conference on Wednesday morning.

The NDP and Bloc Québécois have already said they don't plan to support the budget — which will be presented at 4 p.m. ET by Finance Minister Jim Flaherty — leaving the fate of the minority Conservative government in the hands of the Liberals.

Ignatieff said the budget's fine print will reveal whether the Liberals support the government or bring it down, which could result in an election or a governing coalition with the NDP.

"You go on what's in the cold type and make a kind of overall judgment about whether this is in the national interest," he said.

"And then suppose, just suppose, you think you can live with it. Then you've got the issue of how you can guarantee that it's properly implemented."

Ignatieff, who took over the Liberal leadership from Stéphane Dion in December, said some leaked budget information has already caused him concern, such as the proposed infrastructure funding formula and reported broad-based tax cuts.

Tax cuts

The government has said municipalities will have to match federal contributions for infrastructure projects, something Ignatieff said cash-strapped cities and towns can't afford.

Permanent tax cuts for middle-income Canadians are also in the budget, according to leaked reports. Ignatieff has championed tax cuts for lower-income Canadians and opposes permanent cuts, saying they will only drive the country deeper into deficit.

"It's a detail which I’ll be looking at very, very closely because … we didn't dig ourselves out of the Mulroney deficit of the '90s to be plunged back into a permanent Harper deficit that will dog our capacity to make progress as a country for a long time to come."

While Ignatieff said he doesn't think Canadians want an election in the middle of a recession, he maintained he's not afraid to fight one.

NDP finance critic Thomas Mulcair said he doesn't trust the government, calling the recent series of budget leaks a "cynical attempt to condition public opinion."

Mulcair pointed to reports suggesting the government could impose caps on credit card interest rates.

'Downright cynical'

"We've raised this [with Flaherty] over the past two years and his answers have been downright cynical. He's talked down to us … letting us know that as far as he's concerned, we don't understand the business world," said Mulcair.

The NDP instead believes a governing coalition will best serve the country, he said.

The Liberals, under Dion, and the NDP agreed last month to topple the government by voting against it in a no-confidence vote and form a governing coalition. The coalition also had the backing of the separatist Bloc.

Harper instead asked the Governor General to prorogue, or suspend, the parliamentary session before the vote could occur. Parliament has been shut down for close to two months.

Ignatieff, who took over the Liberal leadership from Dion in December, has appeared lukewarm to the idea of the coalition.