Liberal Leader Michael Ignatieff offered his support for the federal budget Wednesday but said the Tories will be put on "probation" and must provide frequent progress reports.
Ignatieff, speaking in Ottawa, said Liberal support will require that the Tories issue reports to Parliament on the budget's implementation and its cost in March, June and December.
"Each of these reports will be an opportunity to withdraw our confidence should the government fail Canadians," Ignatieff said.
Ignatieff called Tuesday's budget a "flawed" document because, among other things, it fails to extend EI eligibility, attaches strings to infrastructure dollars that may delay projects and jobs, and lacks a credible plan to get out of the deficit situation.
However, he also said the budget includes important concessions such as affordable housing, skills development and measures to make credit available to businesses.
"These measures are only in the budget because the opposition parties did their job, because the Liberal Party in particular remained resolved to hold Mr. Harper to account," Ignatieff said.
"We will not abandon that resolve now."
He said the budget does not include one word about accountability.
"We are putting this government on probation," Ignatieff said, referring to his amendment that the Tories provide frequent updates on the budget's implementation.
"... should Mr. Harper fail to satisfy the expectations of Canadians, we will be ready to defeat him and lead in his place."
Conservative House Leader Jay Hill said that the budget is good news for the many Canadians struggling through the recession.
"I'm very pleased on behalf of the Canadian people that need this assistance," he said Wednesday afternoon.
Responding to the Liberals' amendment which forces the Tories to report back to Parliament, Hill said that the government has always been accountable.
"We will continue to do that," he said. "The amendment just states the obvious."
Both the NDP and the Bloc Quebecois have stated that they will be voting against the budget. In order for it to pass, the support of the Liberals was needed.
NDP Leader Jack Layton was hoping to form a coalition government with the Liberals.
At a press conference shortly after Ignatieff's, Layton attacked Ignatieff over his decision.
"This is the first really important decision in public life that Mr. Ignatieff has had to make... and what he decided to do was to stick with Mr. Dion's unfortunate voting policy of propping up Mr. Harper," Layton said.
"When the Liberals vote for Mr. Harper, with or without a fig leaf of an amendment, they will be casting their 45th straight vote to keep Stephen Harper in office. You can't do that and pretend to be the alternative to Mr. Harper."
Layton said Canadians can't rely on Ignatieff to oppose Harper.
"If you oppose Mr. Harper and you want to replace him, I urge you to join with the New Democrats and support us in the next election," he said.
CTV's Graham Richardson said a senior NDP staffer told him that the "next NDP campaign starts now."
Bloc Quebecois Leader Gilles Duceppe said the Liberals were "letting Quebec drop at its first opportunity" by choosing to support the budget.
"By voting in favour of this Conservative budget, the Liberals will also vote against Quebec," he said in French.
"Just like the Conservatives, the Liberals will also vote against social justice and salary equity and vote against a green economy."
On Tuesday, after months of speculation, Finance Minister Jim Flaherty tabled the budget, which includes $85 billion in deficit over the next five years. The deficit in the 2009-2010 fiscal year will be a shade under $34 billion.
Flaherty's spending plan includes $40 billion in economic stimulus over the next two years in the form of infrastructure spending and tax cuts
