With budget cuts on the agenda, Prime Minister Stephen Harper outlined plans to reduce the deficit, but carefully avoided specifics on possible changes to Old Age Security during the first question period on Parliament Hill after a six-week break.

Harper hinted that changes to Canada's pension system are in the works while at the World Economic Forum in Switzerland last week, touching off a flurry of speculation as to what those changes might be -- including bumping the age of eligibility from 65 to 67 years old.

Opposition parties complained that the Conservatives never mentioned touching Old Age Security when they were on the campaign trail.

"The prime minister stated categorically during the leader's debate . . . that this government was not going to be touching transfers to individuals and transfers to seniors . . . is the prime minister committed to sustaining seniors or is he committed to breaking his promises?" Liberal Interim Leader Bob Rae charged during question period.

Harper responded: "This government ran on very clear commitments and we are acting on these commitments. That commitment is to reduce our deficit to zero gradually without cutting transfers to individuals or to provinces.

"We have the opportunity to look ahead at the challenges that these programs face in the future and to make sure that these programs will be available and viable to future generations. Everyone understands that there are demographic realities that do threaten the viability of these programs over the longer term."

NDP Interim Leader Nycole Turmel said budgets are about choices and the Conservatives are choosing to spend money on F-35 jets, mega prisons and corporate tax cuts on the backs of seniors.

Outlining the government's legislative priorities for the upcoming session, Conservative Party House Leader Peter Van Loan said there are several major pieces of legislation coming.

The so-called omnibus crime bill will be passed within the first 100 sitting days, he told reporters gathered in the House of Commons Monday morning, also noting plans to for the House to pass the law eliminating the long-gun registry by mid-February.

But the government's primary imperative, Van Loan said, is maintaining fiscal balance in the medium-term.

"Canadians can continue to count on our government to move forward on creating jobs and growth, keeping our commitments and getting things done," he concluded.

Van Loan said the government is looking at the medium- and long-term for updating social security benefits for today's demographic reality.

"Twenty years from now, the cost of Old Age Security will be 20 times what it is today," he told CTV's Power Play.

Rae told Power Play that a government pension is more important than ever because of the state of the economy.

"We are aging in a different way than ever before, most people moving into post-65 category don't have a private pension, they don't have coverage" he said. "(OAS) is a basic income support plan that actually has allowed us to cut poverty to seniors over the past 35 years."

Addressing reporters Monday, NDP finance critic Peter Julian said his party will be fighting to ensure whatever cuts come don't impact pensions, health care or job creation.

"We'll be fighting the Harper Government's intention to make significant cuts over the next few months," Julian said.

Given that the upcoming fiscal plan will be the Government's first since winning a majority mandate last year, it is expected to cut spending and eliminate programs that survived during the Tories' years as a minority.

That would be a "slap in the face" of Canadian seniors, Julian told reporters on Monday, encapsulating opposition reaction on the issue.

Besides pensions, the government has signalled its plans to make changes to the pipeline review process and the Immigration Act.

After the last session of Parliament was dominated by legislation held over from the Conservative's minority days, this session gives the government freer rein to pursue its own agenda.

That perception is being fuelled by poll results released Jan. 28, that showed the Conservatives still ahead among decided voters nationwide, with the NDP and Liberals are statistically tied for second-place.

According to the Nanos poll conducted for CTV and The Globe and Mail, the Liberals are gaining some ground at the NDP's expense.

"That fight is sure to heat up as both parties search for new leaders, with the NDP set to choose the next leader of the Official Opposition at their convention on March 24.

But it will be up to interim Turmel to lead the opposition when Finance Minister Jim Flaherty delivers his federal budget expected in late February or early March.

As the first from this majority Conservative government, the budget will be Flaherty's first chance to set priorities without currying favour from the opposition benches.

Federal departments have already been asked to cut their budgets by five to 10 per cent, but Treasury Board President Tony Clement has dropped his own hints that the final cuts might go even deeper.

Besides the long-gun-registry and omnibus crime bills the House of Commons also has to deal with a controversial overhaul of copyright law.

And after signalling his intention to "reset the relationship" with Canada's indigenous population, it remains to be seen whether Harper's plan to fix the Indian Act without rewriting it will satisfy First Nations leaders.

In the meantime, the first order of business for lawmakers Monday is a debate of bill C-25, the Pooled Registered Pension Plans Act.