PENSIONERS would "bear their part of the sacrifices ahead" but not if they were the first group targeted in an economic crisis, a leading advocate says.

National Seniors Australia chief Michael O'Neill welcomed reassurances on Friday from Prime Minister Kevin Rudd that pensioners were still in line for help by the May budget.

The careful choice of words by Mr Rudd that pensioners would receive extra assistance "by" the budget leaves open the possibility they could receive relief before then.

Even so, Mr O'Neill warned that Australia's huge grey army would mobilise if the first thing to go from the government's "to do" list was pension relief.

"We have 280,000 members across the country, 150 branches," he said. "We are capable of activating a visit to every MP, making phone calls to every MP. We'll keep knocking on the door to remind them that pensioners aren't doing too well."

Mr O'Neill was aghast that Finance Minister Lindsay Tanner last week targeted the promised rise in pensions.

Mr O'Neill acknowledged the Commonwealth could be grappling with a more precarious budgetary situation come the May budget, given the global economic crisis.

He said older Australians had waited too long to have their inadequate support payments addressed.

"They recognise as much as anybody the need for fiscal responsibility and caution," he said.

"The concern was that at the first signal of budgetary difficulties by the Finance Minister, the first issue that came up was pensions."

Every $10 increase for single pensioners — the most likely beneficiaries of any budget boost — added $2 billion a year to the budget, Mr Rudd said.

On Friday he reaffirmed the government's commitment after the Opposition seized on the issue and pensioner groups expressed outrage.