The Conservative government is promising to take historic steps to limit federal spending power — but only if federalists win next week's Quebec election.

Lost in all the budget headlines this week was a little-noticed promise to negotiate with the provinces about how to formally prevent Ottawa from spending money in provincial jurisdictions.

Prime Minister Stephen Harper repeated the promise in the House of Commons on Wednesday and said he wants to hold those discussions with a federalist government in Quebec.

Tory Quebec lieutenant Lawrence Cannon was asked whether that means the entire initiative hinges on the defeat of the separatist Parti Québécois in Monday's election.

"That's what I understood," Cannon said of the prime minister's remarks.

"We'll see what happens on election night. But it takes federalists to reform federalism."

Despite the Tories' promises to stay out of provincial jurisdictions, Monday's budget included hundreds of millions of spending in provincially controlled areas such as education, job training and child care.

The budget does not point out how the Tories want to formalize their so-called "open federalism" approach.

Their promise to butt out of provincial business and transfer money to the provinces was a key reason for the Conservatives' electoral success in Quebec, where their gain of 10 seats helped them form a minority government.

The budget does not explain whether the government hopes for a constitutional amendment or some lesser form of recognition that Ottawa will no longer spend in jurisdictions it does not control.

But it does promise future action.

"The government will continue to further clarify roles and responsibilities," the budget says.

"[It] will explore with provinces and territories ways to formalize its commitment to limit the use of the federal spending power to ensure respect for provincial-territorial responsibility."

The Tories also promised to list in future budgets all spending initiatives in areas of shared federal-provincial responsibility.