MORE than two million people are likely to avoid a sharp rise in their private health insurance costs.
The Gillard Government was last night struggling to persuade crossbench MPs to support a reform to reduce the rebate to as low as 10 per cent.
The Government fears defeat of its reform will blow a $3 billion hole in the Budget.
At least three independents - Tony Windsor, Bob Katter and Tony Crook - have raised serious concerns over the impact on rural communities if the 30 per cent rebate is tightened.
Marginal seat Labor MPs - nervous over a public backlash to the carbon tax - have been warned of another campaign by the private health insurance lobby if the legislation goes ahead.
Health Minister Nicola Roxon is expected to introduce legislation in Parliament tomorrow, paving the way for a means test on the rebate.
Under reforms, an estimated 2.4 million people will lose some, or all, of the 30 per cent rebate introduced by the former Howard government to encourage families to take out private health insurance.
Single people earning more than $80,000 and couples or families on more than $160,000 will drop to 20 per cent while the rebate drops to 10 per cent for singles on $93,000-plus and families earning more than $186,000.
A further 740,000 people will lose the entire 30 per cent rebate, including singles earning more than $124,000 and families on $248,000-plus.
Of the six crossbench MPs in the House of Representatives, only the Greens' Adam Bandt is certain to support the Government's reforms. Mr Windsor has voted against the means test twice and said he retained "serious concerns" on the impact of the measure on the bush.
Mr Katter said voters who worked in rural and regional areas would be disadvantaged.
"I'm convinced that people will move out of the private system if we implement means testing, therefore putting more pressure on the public system which is already overburdened," he said.
Mr Crook, the Independent Nationals MP for the West Australian electorate of O'Connor, cited a report by Deloitte that estimated up to 1.6 million people might drop private health care over five years.
Tasmanian Independent Andrew Wilkie said he was considering his position but in May told Parliament he was "yet to be convinced means testing the health insurance rebate is the most sensible thing to do right now".
While Ms Roxon admits it will be tough to get the numbers, she says the proposed rebate changes "are designed to make private health insurance fairer for all Australians". Her comments came as the Australian Health Insurance Association wrote to more than 20 Labor MPs yesterday reminding each of the thousands of voters in their electorates with private health insurance.