OTTAWA - Stephen Harper's campaign pledge not to take Canada into deficit has already come back to haunt him, with Parliament's budgetary officer saying multibillion-dollar deficits are likely unavoidable.

Kevin Page gave sobering news to newly elected parliamentarians Thursday, predicting the government will record the first deficit in more than a decade with a $3.9-billion shortfall next year.

And the situation could be far worse.

Under a worst-case scenario that economists say is not so far-fetched, the federal deficit could hit $13.8 billion next year and $50.6 billion over the next four years.

One thing is certain, Page said, the slumping economy combined with tax cuts introduced last fall - particularly the one-point GST reduction - has brought the era of large federal surpluses to a halt.

"This is not the same year we've seen in recent years. We don't have the reason to believe we're sitting on a much larger unanticipated surplus," he said.

That gave the opposition parties plenty of ammunition to remind Canadians that during the election campaign only a few weeks ago, Harper and Finance Minister Jim Flaherty insisted they would not allow a deficit.

Liberal Leader Stephane Dion pounced on one line in the report as proof the government had mismanaged its books and the economy.

Dion highlighted a passage that said the government is so close to the line this year - as opposed to the $6.6-billion surplus it held last year at this time - because of tax cuts it made last fall. The one-point cut in the GST alone is expected to deprive Ottawa of about $7 billion, Page said.

"It didn't have to be this way. It is the ideological choices made by Mr. Harper and Mr. Flaherty that have put this country's finances at risk," said Dion.

"Mr. Harper leads the biggest spending by a federal government in Canadian history. He spent, spent and spent, he cut the wrong taxes, and he left no buffer and no room to manoeuvre. Now his finance minister is considering a fire sale of government assets to keep the books balanced. "

Flaherty said last week that he is considering the sale of government assets, such as office and commercial buildings, in a bid to balance the books.

On Thursday, he insisted he's not giving up on the possibility of balancing the books. He said he will reveal the most up-to-date numbers when he tables the government's official economic update next Thursday.

"It may not be possible and we're not going to do it artificially but I'm going to try," he told reporters.