In a statement issued Sunday, Kevin Page says his office "will be filing and serving legal notice on all non-compliant" deputy ministers.
He wouldn't provide any further details, saying "this matter will constitute the subject of a legal action" and it would be inappropriate for him to comment further.
Page has said the government has not been open and clear enough about what it intends to cut, and has threatened court action for weeks.
As of the middle of last week, only 23 per cent of federal departments and agencies had handed over the requested financial information, and another 52 per cent had said they were going to comply by last Friday.
Finance Minister Jim Flaherty, appearing on CTV's Question Period Sunday, said Page was overstepping his authority and should be looking at money the government has already spent, rather than future plans.
"Quite frankly, it's outside of Mr. Page's mandate," Flaherty told the interview program.
"He's look at money that's not been spent. That's what we do when we do deficit reduction. We're not spending that money and he wants to have a look at money that's not being spent, rather than the manner in which money is spent, which is actually his mandate."
Set up by the Conservatives in 2006 as part of their government accountability effort, the budget's officer's mandate "is to provide independent analysis to Parliament on the state of the nation's finances, the government's estimates and trends in the Canadian economy."
The finance department, Environment Canada, Citizenship and Immigration, Foreign Affairs and Justice Canada are among the major departments that have refused to divulge the details of their cuts.
NDP finance critic Peggy Nash described the pending court action as a sad day for democracy.
"This is about transparency and providing independent analysis. That's what the Parliamentary Budget Officer does," Nash said.
When the Conservatives created the position in their Accountability Act of 2006, the expectation was that the budget officer would be able to provide Canadians with a real-time view of how their money was spent, she said.
"I think Canadians want to be reassured that there is an independent scruntizing how tax dollars are being spent — or not spent — and that politics is taken out of the equation," Nash added.
She rejected Flaherty's argument that the details on budget cuts fall outside of Page's mandate.
"Rather than accountability and transparency, this government wants to pull a curtain and shroud their decisions," she said.
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