Disability groups have urged Opposition Leader Bill Shorten not to play politics with the National Disability Insurance Scheme (NDIS), describing an increase to the Medicare levy as a fair way to secure its future.

The Coalition wants to increase the levy by 0.5 percentage points from 2019 to fund the scheme, which has reignited a debate about whether or not Labor left a multi-billion funding black hole.

Mr Shorten has supported the Medicare levy, but only for the top 20 per cent of wage earners with a taxable income higher than $87,001.

Disability Advocacy Network's chief executive Mary Mallet told the ABC she did not want to see the future of the scheme used for political point scoring.

"It seems to us that people do understand that it's a fair way to do it, because the Medicare levy is paid in proportion to people's income," she said.

"It is not an unreasonable way to pay for something that befits everyone in the country."

Stop trying to 'bully' Labor, Shorten says

The tax increase has also been welcomed by Australian Federation of Disability Organisations chief executive Ross Joyce, who says it will "put an end to uncertainty".

But Mr Shorten has brushed aside those calls, saying the Coalition should abandon its 10-year company tax plan rather than increase taxes for most Australians.

"I've got a free tip for Malcolm Turnbull — don't give $65 billion away to the largest companies in Australia, use some of that money that you're robbing to actually pay for the NDIS."

"We don't support millionaires paying less and 10 million people paying more."

Mr Shorten said the Prime Minister was trying to "bully the Labor Party" into accepting the Medicare increase for almost all Australians.

Labor has repeatedly denied leaving the NDIS partially funded, pointing to series of long-term savings in the 2013-14 federal budget.

Disability group Every Australian Counts campaign director, John Della Bosca, said he had no doubt Labor was fully committed to the NDIS.

"Labor is free to make whatever points they want about the broader issues in the taxation scheme," Mr Della Bosca told Radio National on Friday.

"But most people in the disability community would very strongly represent to the opposition that whatever points they make, do not do anything that would compromise the bipartisanship for the full funding for the NDIS."

Scepticism on the crossbench

Key crossbench senators remain sceptical about increasing the Medicare levy, which means the Government needs Labor's support to pass the legislation through the Upper House.

Speaking in Western Sydney, Prime Minister Malcolm Turnbull said Mr Shorten was playing politics with the future of the scheme.

"He was a reasonable statesman a few years ago when he said we should increase the Medicare levy to fund part of the NDIS, now we have an opportunity to fund all of it," Mr Turnbull said.

"We call on him to capture the statesman-like qualities he showed some years ago and once again support funding the NDIS, but this time getting it right and funding it completely."

Greens leader Richard Di Natale has said his party would not support the increased Medicare levy for Australia's low income workers.

On Sunday, Treasurer Scott Morrison said he was not willing to engage in horse-trading with the Opposition, saying the tax increase was "a fair measure".