OTTAWA -- Federal political parties may be quarrelling over how best to expand the Canada Pension Plan, but they seem to agree on one thing: Canadians should be saving more for retirement.

The Harper government, long opposed to expanding the CPP, has suddenly decided to consider giving people the option to funnel more earnings into the program in order to grow their nest eggs.

Employment Minister Pierre Poilievre says the Conservative government wants Canadians to save more for retirement.

But opposition parties say a voluntary expansion of the plan doesn't go far enough to ensure people are in good financial shape when they retire.

Liberal MP John McCallum, a former bank economist whose party is proposing a mandatory expansion of the CPP, says people aren't saving enough for their golden years.

The New Democrats also support a compulsory add-on to the national pension plan.

The debate over retirement savings is already shaping up to be a major ballot-box issue for the election campaign slated for this fall.