Prime Minister Stephen Harper returned to work after the holidays with a small cabinet shuffle, promoting two prominent Toronto-area MPs with an eye towards a possible spring election.

Harper's third shuffle in a year moves former TV journalist Peter Kent to the environment portfolio and promotes newly elected MP and former Ontario Provincial Police chief Julian Fantino to minister of state for seniors.

Kent and Fantino both represent ridings in the Toronto area -- where the Conservatives hope to pick up seats in the next election.

"We know there is a threat of an election from the opposition. We don't like it but we take it seriously," Harper said.

The prime minister has cancelled the vacation plans of his ministers and staff, in anticipation the government will be defeated by the three opposition parties in a budget vote expected in March.

"Sources say the government is on high alert, certain the government will be defeated on the budget," CTV's Ottawa Bureau Chief Robert Fife said Tuesday night.

Before Christmas, Liberal Leader Michael Ignatieff said his party would vote against the budget if it contained planned, phased-in corporate tax cuts -- which it will.

Also in the shuffle, Diane Ablonczy was handed Kent's former position of minister of state of foreign affairs (Americas and consular affairs).

Harper promoted Ted Menzies, who served as parliamentary secretary to Finance Minister Jim Flaherty, to minister of state of finance.

Menzies said he will be taking over "part of the load Minister Flaherty has been shouldering."

"We're planning to get back to a balanced budget, he's got a lot of work in front of him," Menzies told CTV's Power Play. "I can take some of his responsibility sitting at the cabinet table so he can deal with other issues.

"The economy has been front and centre for us. We're coming out of this recession looking very good, especially compared to other countries. But the work is not done."

John Baird, who serves as House leader for the Conservatives, relinquished the environment portfolio that he has held on two occasions.

Baird had been serving as Canada's environment minister since November, taking over for predecessor Jim Prentice, who left politics to take a job in the private sector.

Opposition parties were critical of the shuffle, particularly on the environmental file, saying that it doesn't matter who the environment minister is, nothing will be done with Harper in charge.

"You can shuffle the cards all you want, but there's one guy holding the deck and that's Stephen Harper," Liberal MP Martha Hall Findlay told Power Play.

NDP deputy leader Thomas Mulcair said Kent doesn't have the right experience for the job.

"Environment remains an extremely important portfolio for the future. We have moral, ethical and legal responsibilities towards future generations," he told Power Play. "Peter Kent has very little experience in public administration and none whatsoever in the environment."

Green Party Leader Elizabeth May also echoed the criticisms.

"On the climate file, Canada continues to perform abysmally and the buck stops with the prime minister who has dictated that his cabinet minister in the environmental file . . . protect the tar sands and ignore the climate," May also told Power Play. "Peter Kent will not do anything different than that."

The Liberals also criticized the Conservatives for expanding the size of cabinet, noting it has swollen from 26 to 36 members since 2006.

"Harper let his cabinet expand by 10 ministers and allowed their office budgets to soar by 16.5 per cent over the last two years – a $10 million increase," the Liberals said in a news release.

‘Staying the course'

Harper described the appointments as a way to ensure "prudent financial stewardship" from Ottawa, as the national economy struggles to recover from the recession.

"Canadians have just come through a year during which the rewards of prudent financial stewardship, and of appropriate, well-timed stimulus measures have yielded dividends in jobs and growth," Harper said in a statement about the new appointments.

"It is a good note upon which to start a new year. However, the global recovery is fragile. And there are still far too many jobless Canadians for whom the recovery has yet to become a full reality. That is why the economy remains the No. 1 priority for Canadians, and must remain the No. 1 priority for our government."

The "small cabinet shuffle" was confirmed by Harper's spokesperson, Dimitri Soudas, via Twitter on Tuesday morning.

Soudas described the move as "staying the course with a competent team."

With files from The Canadian Press