Apparently wary of the chance the opposition could force a federal election call as early as next week, Prime Minister Paul Martin has cancelled a planned trip overseas.

Martin was to have visited the Netherlands and Russia on a three-day swing beginning May 7th, but in an announcement Monday, the Prime Minister's Office said his plans have changed.

"With the Conservatives and the Bloc Quebecois threatening to force an election, it makes best sense to ensure that the prime minister is here at home and available to Parliament,'' PMO spokesperson Melanie Gruer said Monday.

"Lots of things are happening these days, so it makes sense that he's home," she told The Canadian Press, adding that Martin also wanted to attend the official opening of the Canadian War Museum in Ottawa on May 8.

Instead, Governor General Adrienne Clarkson has been asked to make the trip to Apeldoorn and Moscow, where she will represent Canada at ceremonies commemorating the 60th anniversary of the Dutch and Soviet liberation during the Second World War.

Commenting on the announcement Monday afternoon, Conservative leader Stephen Harper said the prime minister's decision sends a clear signal.

"It's all consistent with the campaign the prime minister is now running," Harper told reporters in Toronto. "The prime minister says he doesn't want an election, but near as I can tell, he's called one and begun campaigning."

Martin's tenuous Liberal minority government could find itself on the rails in the coming weeks, as it is tested not only by an imminent vote on its federal budget plan, but also opposition non-confidence motions.

If the government loses such a vote, it would be forced to resign or call an election.

Counting on the unguaranteed support of the entire federal NDP caucus, the Liberals still control just 151 votes in Parliament. That's two less than the 153 seats of a combined Bloc Quebecois-Conservative block.

There are also three votes controlled by independents Carolyn Parrish, Chuck Cadman and David Kilgour.

With files from The Canadian Press