Any possible change to Old Age Security would have a dramatic domino effect on other social programs and income supplements, interim Liberal Leader Bob Rae said Wednesday.

Speaking after a weekly caucus meeting with Liberal MPs, Rae said seniors also apply for the Guaranteed Income Supplement and social programs offered by provinces based on Old Age Security. The GIS goes to poor seniors to try to bring their income up to the poverty line.

"What Mr. Harper is doing is starting a domino effect which downloads on seniors, downloads on poor seniors, downloads on provinces, downloads on municipalities and has a much more dramatic effect than what he's pretending," Rae said Wednesday.

Any cut to retirement income would be contrary to a promise not to cut transfers to the provinces or to people, he said.

Prime Minister Stephen Harper mentioned in a speech in Davos, Switzerland, last Thursday that he wants to look at retirement income and make sure it's sustainable in the future. His office says while there are four taxpayers for every senior in Canada right now, by 2030 there will be two taxpayers for every senior.

On Monday in the House of Commons, he said he won't cut Old Age Security. All Conservative MPs who responded to a question on retirement income said they would look at ways to make it sustainable and that no cuts to be made would affect anyone now collecting or soon to collect OAS.

In question period Wednesday, Harper said the government will protect seniors now and those who will be seniors in the future.

"A senior will not lose a single penny, nor one near retirement. But we're dealing with those people far off in the future who are very worried about their income security because they understand the pressure the system is under," he said.

Opposition MPs are maintaining pressure on the government over the possibility of OAS cuts, but so far there's little information on what exactly any changes might entail.

Rae said there wasn't anyone in the audience at the World Economic Forum in Davos, a conference of world leaders and business elite, who has to worry about the GIS or old age pensions.

"If they’re not going to do anything, then what was that discourse from the alpine perch about? What was that? Was that just trying to make a bunch of people in the audience happy?" he said.

"Do we know exactly what those changes are? No. I don’t know.… To go to Switzerland and make an announcement about pensions and not have a followup is, frankly, preposterous."

Harper must be clear about changes, NDP say

Interim NDP Leader Nycole Turmel says that despite a lack of information on what the government may have planned, she wants to maintain pressure on the Conservatives to clarify their intentions.

Turmel says she met with the Canadian Association of Retired Persons and they will maintain pressure on the government together.

"We want him to be clear, or his party, to be clear where they are on the OAS. We want to make sure that our old age people have the money or the subsidy to be able to live up till the end of their life," she said.

"We want really for him to say openly no, we won't touch it in future, we won't touch it now. We want his plan. And it’s so dangerous when we start to throw out messages outside the country, then come back to the country and try to say no, it isn't as bad as that."

The NDP said it would use its Opposition Day on Thursday to debate a motion stating: "That this House rejects calls by the prime minister to balance the Conservative deficit on the backs of Canada's seniors by means such as raising the age of eligibility for Old Age Security and calls on the government to make the reduction and eventual elimination of seniors' poverty a cornerstone of the next budget."