Former prime minister Tony Abbott has admitted his own side of politics is responsible for much of the cost blowouts in the NDIS.

But a former Liberal National Disability Insurance Scheme cabinet minister has spoken out about Labor blocking his attempts to stop the scheme “bankrupting” Australia.

As Liberal opposition leader in March 2013, Mr Abbott backed then Labor prime minister Julia Gillard’s National Disability Insurance Scheme despite having misgivings about eligibility criteria.

Labor went on to lose the election later that year, and Coalition governments had responsibility for the NDIS from 2014 to 2022 under Mr Abbott and his Liberal prime ministerial successors Malcolm Turnbull and Scott Morrison.

“I think I pretty well anticipated the inevitable problems with the scheme,” Mr Abbott told The Nightly.

“The pity is that successive governments didn’t address them better and sooner.”

Mr Abbott declined to say if he regretted backing the NDIS in opposition.

But he argued he had raised concerns 13 years ago, after Labor put forward legislation to create an individual-centred scheme based on Productivity Commission recommendations.

“If you read my Hansard speech from the time, I think you will find plenty of caution and some important reservations,” Mr Abbott said.

“Who is entitled to, plus NDIS governance, are the key issues that need to be addressed for the scheme to be sustainable over the long term.”

In its first full financial year, in 2014-15, the NDIS was envisaged to support 460,000 participants and cost $22 billion a year but it now as 760,000 participants and costs $52 billion a year.

The growth had been gradual but escalated in the later years of the Coalition government.

Former Liberal NDIS minister Stuart Robert, in 2020, moved legislation to introduce tighter eligibility criteria and independent disability assessors, only to have Labor in opposition campaign against the move.

Bill Shorten, the shadow NDIS minister at the time who had created the original project, had enlisted disability advocates to campaign against moves to curb growth rates, with the Coalition lacking the numbers in the Senate to get its legislation passed.

“In 2020, the issue was unless there were changes made to the legislation, this would bankrupt the country, that’s now turned out to be true,” Mr Robert told The Nightly.

“They refused to support us and actively attacked, actively undermined, coming out and saying that we hated the scheme, we never supported it and only Labor could fix it, just rhetoric, it’s just noise.

“They were positioning for an election win but unfortunately, they just didn’t have an eye to what it needs or what it takes to govern.”

Mr Robert argued Labor in Government is now being forced to remove 160,000 from the scheme because they blocked his push to tighten it, adding the Coalition now had little choice but to back Labor in Government.

“I don’t think the Parliament has any choice but to back the Labor Party,” Mr Robert said.

“We were never going to cut people off the scheme — Labor’s going to cut 160,000.

“They’ve gone further than we were going to go, cutting back on community participation. We never entertained any of that.

“Because they didn’t support us in 2020, here they are going further and harder.”

The NDIS now has 760,000 participants with Health and NDIS Minister Mark Butler this week arguing the numbers would grow to 900,000 by the end of the decade.

Labor is now seeking to tighten eligibility criteria, and reduce the number to 600,000 by 2030 by putting autistic children on a new Thriving Kids program run by the states.

“When we went to get support to do exactly what they’re doing now, not only did they rail against us, they got the sector to rail against us, refused any support and yet here’s the minister coming out saying that he would do this anyway because it’s the right thing to do,” Mr Robert said.

By 2021-22, total payments to participants had hit $28.6 billion, a $5 billion increase from the previous financial year with the average payment per participant of $55,200, up from $32,300 five years earlier.

The average payment grew to $65,800 during the last financial year.

Treasury is now forecasting the NDIS will cost $52 billion a year and grow to $64 billion by 2028-29 without major changes.

In the House of Representatives in March 2013, Mr Abbott supported the NDIS, making it a bipartisan gesture.

In a hung parliament, he was an otherwise obstructive opposition leader who had campaigned about Labor’s carbon and mining taxes and argued the minority Labor government was illegitimate for horse trading with the Greens and independents on legislation.

“Quite often in this chamber, I am accused of a relentless negativity,” Mr Abbott said at the time.

“It is always unfair, but in this case it is false — because when it comes to the National Disability Insurance Scheme, I am Dr Yes. I always have been, always will be.”

In that same speech, he raised concerns about the unknown design elements from the role of state governments to whether it would resemble Medicare for people with disabilities.

“We still do not know who will be eligible for the NDIS,” Mr Abbott said in 2013.

“We do not know what is covered by the NDIS. We do not know the extent of coverage by the NDIS. We do not know the precise role of the states in the operations of the NDIS, if any.”