Opposition leader Bill Shorten used his Budget reply to commit to supporting a Medicare levy increase in order to fund the NDIS, however, only for those earning more than $87,000.
Pressed on the costing for the measure, he said the plan would raise $7.8 billion over four years and about $50 million over 10 years.
The revelation comes after the opposition leader was quizzed twice on ABC Radio on Friday about an exact figure, in which he said: "I'll have to go and check our final figures and the costings."
In the Budget reply, Mr Shorten said he will also fight to retain the temporary Budget deficit levy, which is scheduled to end on July 1, and called it a “fairer” plan which would see Australia’s highest income earners hit with a tax rate of nearly 50 per cent.
“I actually think it's fair to ask people with a lot of money to pay a little bit more,” Mr Shorten told reporters on Friday.
“Let me be clear, when there is a sustainable surplus we will re-examine all of the tax brackets,” he said.
Labor’s deficit levy is supported in-principal by the Greens and the Nick Xenophon Team, although Senator Xenophon is reserving his full judgement until after he briefs his team.
“It's been our view that a deficit levy on high income earners would not be unreasonable to continue, considering we still have a deficit,” Senator Xenophon said.
“I would have thought that top 3 per cent or so of income earners should be able to pay that little bit more tax.”
Labor’s plan would see the top marginal tax rate, on incomes over $180,000, set at 49.5 per cent.
Under the government's plan, the NDIS would be funded via a 2.5 per cent Medicare levy on all taxpayers which it said would raise $8.2 billion over three years from when it starts in 2018.
Mr Shorten accused the government of taking the NDIS hostage because it wanted to give a “truckload of money to the top end of town and their mates there".
Related reading
Shorten's budget reply targets top earners
"I don't accept this simplistic equation which says the only way we can provide Medicare or NDIS is by asking people on $50,000 a year to pay more income tax - that is rubbish," Mr Shorten said.
The government is accusing the Labor Party of hypocrisy, because it increased the Medicare levy of 0.5 per cent across the board when it was in government.
On Friday Treasurer Scott Morrison accused Mr Shorten of playing “class war politics with the disabled”.
Mr Morrison labelled Mr Shorten’s budget reply speech political “Billdust”.
