MORE than 900,000 Victorians would face tax increases under a Tony Abbott-led government, thanks to his pledge to close off the low-income superannuation concession.
Across Australia, 3.6 million people would lose the concession, which reduces to zero the normal 15 per cent rate applied to super contributions.
The concession, which costs the budget about $1 billion annually, was introduced by the government last year and was to be paid for by revenue raised by the mining tax.
It benefits people earning less than $37,000 a year who would otherwise have no concessional advantage from superannuation.
At its maximum, it is worth $500 annually, but most people get less than that.
The number of people affected by its removal dwarfs those likely to pay more tax if the Gillard government moves, as expected, to increase concessional superannuation rates for the top few per cent of income earners.
Superannuation policy has emerged as a class-war issue between the parties.
Labor accuses Mr Abbott of callously hitting 3.6 million of the poorest taxpayers while opposing changes to curb disproportionate tax advantages for the wealthy.
Treasury figures show the top 5 per cent of income earners, who have a greater capacity to direct savings into super, obtain a combined benefit of nearly $6.5 billion a year.
The opposition counters that Labor is preparing to soak the rich in a bid to replace its underperforming mining tax and salvage its budget position.
Last week Mr Abbott promised to make no ''negative or unexpected'' changes to superannuation for a whole parliamentary term if elected in September.
Income figures supplied by the government show some electorates set to be crucial in the election have large numbers of people earning less than $37,000.
These include Tony Windsor's New South Wales seat of New England, which has 27,000 people earning under $37,000, and the government's most marginal seat in the country, Corangamite, with about 25,000.
Last year, a key superannuation body called on the opposition to leave the measure in place.
''The low-income super contribution scheme was introduced to address this inequity in the superannuation system where Australians earning less than $37,000 previously did not receive a tax concession,'' said the Financial Services Council's John Brogden.
''To reverse this initiative would be a gross injustice.''