The Bloc Québécois wants the NDP to explain how it will try to win Quebec's approval for the Constitution before Canadians go to the polls on Monday.
Speaking in the riding of Chambly-Borduas, east of Montreal, Bloc Leader Gilles Duceppe accused his NDP counterpart of offering vague promises to Quebeckers.
"When there is a problem, usually you have a solution," Mr. Duceppe said of Jack Layton's musings on the Constitution. "I'd like to be able to judge what he is offering us, but I see nothing except he says the matter has to be settled."
Among other things, the Bloc Leader asked for concrete details on matters like Ottawa's spending powers in areas of provincial jurisdiction, and a proposal to impose Quebec's language-laws in federally regulated industries in the province.
In Winnipeg, Mr. Layton rebuffed criticism that his promises of openness to Quebec are empty - though he still didn't provide any indication of what kind of changes to the Constitution he might support to secure Quebec's signature.
"[Mr. Duceppe]has a completely different approach from ours. His goals are completely different. We share the concept of a Canada and Quebec, together, strong. And we are uniters not dividers."
The NDP Leader instead argued that defeating Stephen Harper's Conservatives and social-policy initiatives would constitute a new openness to Quebec.
"The first thing to do is to rid Ottawa of Stephen Harper's government, who doesn't respect Quebec, who does not respect Quebec families. And that's the first important step. And to respond to the needs of Quebecers with initiatives in the House of Commons, which can improve the lives of Quebecers."
"Like our bill, which Mr. Duceppe supported, for the language of work in federally-regulated workplaces. It's a good example of the type of thing we will do."
Mr. Layton said he did oppose a bill that would enshrine Quebec's right to withdraw from federal social programs in areas of provincial jurisdiction and receive the money from Ottawa instead. But he noted the NDP has included that right to withdraw in specific social-policy initiatives.
"Our bill on daycares, for example, has a clause which specifies exactly the same thing. And the Bloc voted for it. And it's a good example, we have several others before the House of Commons. Our bill on post-secondary education, same thing, public transport, social housing. We have put in place that asymmetrical federalism in specific laws."
The Bloc is spending the last week of the campaign battling the growth in NDP support in Quebec, which has profoundly disturbed the province's political landscape. Mr. Duceppe acknowledged he hadn't foreseen the strength of the NDP in the last stretch of the campaign.
"We didn't expect it at that level, but we're not the only ones," he said.
The Bloc currently has 47 seats in Quebec, while the NDP has only one MP, Thomas Muclair, in the province.
However, the NDP lead in polls in the province has forced the Bloc to spend much of this week campaigning is ridings that are normally seen to be party strongholds.
"We don't make vague promises," Mr. Duceppe said. "Our promises are clear and our policies are known."
Bloc supporters are obviously concerned about the rise of the NDP, pointing to reports that a number of the party's candidates in Quebec have no political experience or few links to their ridings.
"Apart from Jack Layton and Thomas Mulcair, we don't know them. Will people vote for phantoms?" asked Micheline Groleau.