OTTAWA - When the House of Commons resumes Monday, there will be a short period of non-partisan esprit de corps — but then an ideological battle begins in earnest between the Conservatives and the NDP on everything from the economy to crime.

Canada's 41st Parliament gets back to business in the morning with tributes to late NDP leader Jack Layton, his absence felt more keenly because he spoke in the Commons until the very last day of the spring session in June.

New Democrat MPs enter the chamber knowing this was where Layton was in his element. Many are still grieving.

"It's been really difficult," says MP Brian Masse. "For me, I lost more of a friend than a leader when Jack passed away."

Liberal House Leader Ralph Goodale says a more civil debate in the Commons would be a lasting memorial to Layton.

"He would never want the place to be wishy-washy, or boring, or all watered down and meaningless. Parliament is a place where there is, by definition, a clash of ideas," Goodale says.

"But we need to find the dividing line between vigorous, aggressive, appropriate debate and the nasty side of politics that is personal and mean."

While all parties are promising this majority Parliament will be different — more respectful, and more focused on policy than quick political gain — there's every sign that it will be acutely polarized.

Conservative House Leader Peter Van Loan said his party will be focused primarily on the economy, in light of the worldwide economic downturn and especially the precarious situation in the United States. That means implementing more elements from the 2011 budget such as tax credits for job creation. Passing free-trade deals with Panama and Jordan are also part of that agenda.

The Conservatives have balked at introducing any new stimulus spending as they continue on a track to eliminate the deficit by 2014, although Finance Minister Jim Flaherty recently said some "flexibility" might be necessary.

Already, the Tories are promising to pick apart all of the NDP's economic policies with a degree of attention they haven't applied before.

"Our approach will be that we have to have a sound approach fiscally, that lower taxes and smaller government are an important part of successful stimulus and job creation," Van Loan said in an interview.

"I expect the NDP will be arguing a different perspective, that we should go deeper in debt, we should spend more, and that's the right way to go about job creation. That's a legitimate debate. I know where I come down on it."

Other legislative priorities for the government this fall are the passage of a massive omnibus crime bill on issues ranging from young offenders to terrorism; the dismantling of the Canadian Wheat Board's marketing monopoly in the West; and a bill to redistribute and add seats in the Commons.

The NDP will frame the debate as one between cold-hearted, out-of-touch Conservatives and a compassionate, pragmatic official Opposition.

"They love to come up with things that will be divisive with the public, posture that they're doing something serious about law and order," said NDP House Leader Thomas Mulcair.

"Most of what they're done so far has been smoke and mirrors, but I think that's where most of the battle lines will be drawn this fall session.

"There will also probably be some strong attempts to reduce government spending, and based on what we've seen with the Conservative government, they tend to hurt the public with their choices in terms of reducing government spending."

The Liberals don't appear to figure in the rhetoric of either the NDP or the Conservatives, although experienced interim Leader Bob Rae is likely to outshine his NDP counterpart, Nycole Turmel, in the Commons. The NDP caucus will also be dividing its attention between the action on Parliament Hill and the race to succeed Layton.

Goodale says the Liberals will have a "huge opening" if the NDP and Conservatives choose to polarize the debate in the Commons.

"They would like to peddle the notion that everything would be better off if we had this polarized situation where there's just one party on the right and one party on the left and everything is a straight black or white, good or bad, right or wrong, kind of decision," said Goodale.

"But if you want a good example of the havoc that ultimately results from that kind of approach, just look at the simplistic, polarized politics of the United States last summer."

Prime Minister Stephen Harper will pop in and out of the Commons all season. On Tuesday, he's expected to attend the United Nations General Assembly in New York. Later in the fall, he'll go as far afield as Australia and potentially China for summits and official visits.