Superannuation Minister Bill Shorten has all but ruled out further changes to the taxation of super in next month's budget, after the federal government confirmed the budget had blown out by $7.5 billion since October.
The comments come as new figures suggest double-digit returns are still likely in the year to June 30, despite falls in March and a weak start to April.
Research group SuperRatings said the median balanced fund - the most common super category, with between 60 and 76 per cent invested in growth assets such as shares - fell by 0.2 per cent last month, the first slip this financial year. The fall was driven by a 2.2 per cent fall in the S&P/ASX 200 Index in March.
"Despite the stumble, the median financial year to date performance for the 2012/13 year sat at 12.5 per cent as at the end of March and funds remain on track to deliver the strongest financial year performance since at least 2007," SuperRatings said.
The research group said that the combination of the Boston Marathon bombings, poor Chinese economic data and softer commodity prices were "all shifting investor focus onto global risks", leading to estimates that super funds fell by 0.3 per cent in the first 19 days of April.
Investment researcher Morningstar said last week the median fund within the multi-growth option, the most common category, was likely to "end the financial year with double-digit returns, unless a large negative result is recorded for the last quarter".
The need for savings was highlighted by comments from federal Treasurer Wayne Swan that weaker terms of trade and a persistently high Australian dollar had stripped $7.5 billion in revenues over the past six months.
But Mr Shorten said on Monday that he had "made it incredibly clear that not only do we not see the budget as being what drives superannuation. What I see drives superannuation policy is increased life expectancy, the dream of a comfortable retirement."
He also stepped up his attacks on the Coalition's promise to repeal the low-income super contribution (LISC), a government super payment of up to $500 a year for people earning up to $37,000.
"Mr Abbott's plan is to rip away up to $500 from the hands of those Australians who need it most," Mr Shorten said, saying 2.2 million of the 3.6 million affected were women.
But shadow superannuation minister Mathias Cormann said Labor would also scrap LISC, because it couldn't afford it. "And they would hit other super savers hard with more new Labor Party taxes targeting people's retirement savings," he said.