OTTAWA - A contrite Canadian Prime Minister, battling to avoid defeat at the hands of opposition parties over a cash-for-favors scandal, pleaded on Friday for more time in office while dismissing demands that he resign.

In a rare national address on Thursday, Paul Martin apologized for the scandal and said he would call an election as soon as an inquiry into the alleged kickbacks finished its work in December.

But opposition parties mocked Martin's offer and seem set to topple the minority Liberal government next month and force a June 27 election. Canada's last election was in June 2004.

Martin appeared on two of Canada's main television networks early on Friday at the start of a media blitz to persuade the country that an election should wait until after the inquiry finishes its work.

The inquiry, headed by Justice John Gomery, has heard that money from a sponsorship program, designed to promote national unity and counter separatism in French-speaking Quebec, saw big kickbacks going to the Liberals in return for government contracts.

"I believe that if the opposition accepts the fundamental fairness of allowing Judge Gomery to make his report once all of the facts are in ... then we can focus on the matter at hand, which is governing the country," Martin told CBC.

"So it's up to the opposition. I very, very much hope that they'll understand that and I think fair people will."

The scandal is the biggest crisis to hit the Liberals since they took power in November 1993. Polls indicate that if an election were held now the main opposition Conservative Party would win power, albeit with a minority government.

The leader of the separatist Bloc Quebecois said the only thing which would prevent him from pushing for a June election would be if Martin resigned. Asked whether there was any chance Martin might quit, the prime minister's chief spokesman, Scott Reid, told Reuters: "No."

The Conservatives dismissed Martin's proposal and said they had not yet decided when they would try to bring down the government.

"On what basis am I to prop up this government? We have to have a positive reason. I don't like what's going on," Conservative leader Stephen Harper told CTV.

Harper said he would have a clearer idea of when to push for an election at the beginning of May, when Parliament returns after a week-long break.

Martin, who was finance minister at the time of the scandal, has already accepted overall responsibility for what happened but is now making more heartfelt apologies.

"I do regret very, very much that the government -- and that I -- was not more vigilant in checking it out ... I do very much regret that we did not know," he told CTV.