Liberals made a sudden move to control the timing of a possible election, by restricting when the opposition will be able to introduce a motion that could possibly topple the minority government.

Liberals accused Conservatives of trying to "hijack" the legislative agenda, while Conservative leader Stephen Harper said the government is on a "death watch."

Harper was furious, and hinted his party will no longer help the Liberal government remain afloat.

The fury happened Monday night, when government House Leader Tony Valeri cancelled the upcoming "opposition day" scheduled for Wednesday.

CTV's Mike Duffy told Newsnet the government heard through the grapevine that Conservatives' opposition day motion would have allowed opposition parties to set the timing of future opposition days.

That would have given the Conservatives total control over the timing of a non-confidence vote that could bring down the government.

"When a government starts trying to cancel dissent or avoid dissent ... is when it's rapidly losing its moral authority to govern," Harper told reporters Monday night.

"Now, if they don't even want to work with the one party who has cut them a break from time to time, so be it. They do so at their own peril," he said.

Valeri said the opposition was trying to take over the legislative agenda, "and frankly, I would not allow that."

"When somebody tries to hijack standing orders and hijack government business, I have a responsibility to Canadians -- and frankly, to the institution -- to make sure that government is able to bring forward its agenda," Valeri said.

Opposition parties are allotted about 20 opposition days per session to put forward motions of their choosing.

The parties are given days on a pro-rated basis, said Duffy.

"Part of the political game here is we have eight opposition days remaining between now and June 23," he said.

The opposition now fears the government will schedule all the opposition days towards the end of the parliamentary session in June, Duffy said. That would have Canadians looking at a summer election, in late July or early August.

Asked if he would put all the opposition days off until the end of the session, Valeri said, "What I am committed to is providing all those opposition days in this cycle."

Conservative House Leader Jay Hill hinted his party could look to topple the government some other way, perhaps through an upcoming budget-implementation vote.

"We will be looking at any tools that are available to us to consider holding this government accountable,'' he said. "We have been endeavoring to work in a co-operative manner with this government, but now the gloves are off.''