QUEBEC CITY - Quebec's political parties have banded together to take the NDP's Jack Layton to task, in an early hint of the political challenges he will face in his new role as Opposition leader.

All three provincial parties agree the province would need only a simple majority in a referendum -- 50 per cent plus one vote -- in order to separate from Canada.

Their statements come a day after Layton carefully tiptoed around the question of how many votes it would take.

The episode is an early example of what could prove to be a perennial dilemma for Layton as Opposition leader, now that he has supplanted the Bloc Quebecois: how to satisfy his new supporters in Quebec, without alienating others in the rest of Canada?

On Wednesday, Layton seemed to endorse the decade-old Clarity Act, which sets conditions for Quebec independence.

The Act is unpopular amongst nationalist Quebecers -- and is repudiated by all political parties in the province -- because it gives the House of Commons the right to decide what constitutes a clear referendum question.

Layton also shied away from reporters' repeated invitations to explicitly state whether he supports a popular position in Quebec that 50 per cent plus one vote is enough to secede.

He simply uttered a reference to the party's Sherbrooke Declaration -- a summary of the NDP's Quebec policies -- which states "the NDP would recognize a majority decision (50% + 1) of the Quebec people."

But Layton's reluctance to state his position out loud obviously irked Quebec's political class.

It also earned him a front-page story in Le Devoir newspaper that spoke of a rift within the NDP caucus, which pitted Layton against his Quebec MPs.

Provincial Intergovernmental Affairs Minister Pierre Moreau stressed that Quebec -- not Ottawa -- has the final say about whether to stay in the federation or not.

"We've adopted laws on this specific question," he told reporters in Quebec City.

"Here in Quebec, the rule that applies is 50 per cent plus one.

"If Mr. Layton has a different opinion he's free to express it. But that won't change the rule that applies here."

The opposition Parti Quebecois was even less charitable. That party hopes to win an election within the next two years and, perhaps, hold a referendum on Quebec independence afterward.

PQ Leader Pauline Marois accused Layton of distancing himself from statements he made during the election campaign.

"Now that he is in the House of Commons he will backtrack on his promises," she warned.

"I think he is revealing his true face."

The controversy is a sampling of the issues that threaten to dog Layton's tenure as Opposition leader.

His caucus has a heavy contingent of Quebec nationalists, attracted to the party by many of the policies contained in the Sherbrooke Declaration.

But as Layton eyes expanding his party's base outside Quebec, he may find it difficult to reconcile the demands of nationalists with those of more traditional federalists.