The Federal Opposition's move to block the tightening of pension eligibility has been foiled by the Greens.

Social Services Minister Scott Morrison said the Greens would support the Government's $2.4 billion savings measure — the budget's biggest.

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"As a result of these changes it is estimated more than 170,000 pensioners with low and modest levels of assets will have their pension increased by around $30 a fortnight from January 2017, when these changes take effect," he said.

But Labor opposed the changes because they will reduce part pensions for 235,000 people and eliminate them entirely for 90,000 current recipients.

"The Liberals are coming after your pension and the only thing standing between pensioners having significant cuts to their pension and Mr Abbott is the Labor Party," Opposition Leader Bill Shorten said earlier on Tuesday.

Greens leader Richard Di Natale said the party's support was conditional on the Government considering changes to superannuation in its Tax White Paper.

"The Government has agreed to give special consideration to retirement incomes in its Tax White Paper, which means we can finally look at superannuation as part of the equation," he said.

"It makes the pension system a lot fairer, it reverses the changes that the Howard government introduced back in 2007, which we opposed back then.

"So what they allow us to do is have a much more thorough and detailed investigation into retirement incomes.

"We'll have a separate component of the Tax White Paper that looks specifically at this issue, and we can stop this piecemeal approach where you cherry pick one part of the budget, rather than looking at the issue of retirement incomes, which is what we should be doing."

While opening the issue up for more consultation, the Government is maintaining its position on superannuation and associated tax concessions.

"The Government has made it crystal clear that our policy, when it relates to superannuation and particularly taxation and the flexibility of people's arrangements, is unchanged," Mr Morrison told 7:30.

"We won't be making any changes adverse to those arrangements this term, and we have no plans to do that beyond the next election."