Reports say the government has decided to dump its deeply unpopular plan to reduce the rate of indexation for the age pension and will make up the lost revenue by changing eligibility criteria for the part-pension.

But Mr Abbott was tight-lipped when asked about the reports on Saturday.

"I want to assure people this is a budget that will be measured, responsible and fair," he told reporters in Sydney.

"It's a budget that will be good for jobs, growth and opportunity."

But as for specific budget announcements, people will have to wait until May 12, he said.

Dumping the pension indexation policy will be as popular with Mr Abbott's backbench as it will be with pensioners themselves. Coalition dissenters have been urging the Prime Minister to shed this final policy "barnacle" for months.

In that sense, the decision will help shore up Mr Abbott's leadership against further attack.

Finance Minister Mathias Cormann was also asked about pensions but said only that the government was fully committed to making sure the system was sustainable.

Currently, aged pensions are indexed to whichever is higher out of inflation and male average weekly earnings. The government had wanted to index only to CPI, which is mostly lower, in a bid to save $23 billion over 10 years.

Labor's families spokeswoman, Jenny Macklin, said any changes to the part-pension would amount to another broken promise by Mr Abbott.

"Tony Abbott should come clean how many part-pensioners will be worse off by this latest attack and how many will be kicked off the pension altogether," she said. "Any part pensioner with assets is at risk of a pension cut under this new broken promise."

Mr Abbott on Saturday also moved to hose down new rumours of a possible early double-dissolution election.

"I should say it is my firm intention to deliver on the mandate that the public gave us and when the public elected us, they expected us to govern for three years and that is absolutely what we intend to do," he said.

The government also announced Australians who have moved overseas for more than six months will be required to pay back the same amount of their HECS debt as they would if they were residing in Australia.

The change will take effect in July 2017 and is expected to improve the government's bottom line by $140 million over 10 years.