About 150 jobs stand to disappear from the community mental health sector when the Federal Government rolls mental health funding into the National Disability Insurance Scheme on July 1.

The Mental Health Coalition of South Australia predicted the first substantial job loss under the new Marshall Liberal Government, and the biggest in the history of the state's mental health sector.

Executive director Geoff Harris described the job losses as a "tsunami" that had already hit the sector, with the "wipe-out" already commencing.

"When you lose a skilled workforce like this and key programs cease to exist, you put more pressure on an already-overworked system," he said.

"You put more stress on families and carers, you find people presenting at emergency departments and worst of all, you leave vulnerable people in the community at risk of self-harm and suicide."

More than 2,000 people without support

The MHCSA said highly skilled and qualified mental health support workers were being told they will not have a job beyond the financial year as Commonwealth funding will be pulled out of mental health programs.

It is estimated that each of these workers would support about 10-15 people in a mental health program in South Australia — resulting in up to 2,500 left without support.

The cuts are being blamed on the delayed rollout of the NDIS — with the State Government releasing a statement on the issue, but not answering questions on Monday.

The MHCSA said highly skilled and qualified mental health support workers were being told they will not have a job. ( Unsplash: Max Sandelin )

The Commonwealth Department of Social Services argued that the uptake of people living with mental illness in to the NDIS was more than 70 per cent — but the Mental Health Coalition data has it around 30-35 per cent.

"These mental health services that are currently funded are really effective in supporting people to stay well in the community and keep out of needing to use emergency and acute care services … so what we will see with a reduction in support for mental health services is more people needing to use already-overcrowded acute and emergency services," Mr Harris said.

"Organisations are already giving notice to their employees that they don't have work for them from first of July, so it is critical that this gets addressed soon."

'Wipe-out' of the mental health sector has started

Mr Harris said the job losses would create a "massive gap" in support for South Australians, with mental illness which would require $8-10 million to fix in the coming financial year.

The Commonwealth Government promised $92.6 million in the federal budget for services to continue supporting people, however the money would be over four years and for all of Australia.

Mr Harris said that would mean less than $2 million a year for South Australia — to replace the $40 million per annum previously invested for mental health programs.

"We keep talking about the tsunami, well it has hit the sector and the wipeout has started," he said.

SA political candidates at a mental health forum ahead of the 2018 state election. ( ABC News: Nick Harmsen )

"We just need the Commonwealth and the State [Government] to not allow this to happen because it will be a disaster to have that huge reduction in capacity to support people.

"Obviously, people won't be supported as well as they are now and that is going to have a huge impact on those individuals and their families."

The MHCSA said it had been contacted by one regional worker who said she managed 20 clients — but only one of them had managed to get in to the NDIS while the other 19 were promised continuity of support — however, there was no program to support them from June 30.

'This is the kind of stuff that NDIS was meant to fix'

Disability advocate Kelly Vincent said to hear there were more people at risk of being disadvantaged when they are the most in need of services was absolutely appalling.

"This is the kind of stuff that NDIS was meant to fix and both the federal and state government are not willing to step in to ensure that vulnerable people get the services they need," she said.

"It is very disappointing that the State Government aren't making themselves available to speak about this issue today, particularly when they are a Government that rose to power criticising the previous government's inaction on health issues."

In a statement released by the State Government, Minister for Health and Wellbeing Stephen Wade said the Government was increasingly concerned that the transition to the NDIS was creating gaps in services for South Australians with mental health issues.

Mr Wade urged the Federal Government to work with community mental health service providers to ensure continuity of services.

The Federal Government also released a statement with Social Services Minister Dan Tehan, stating that the Government was committed to providing continuing support for mental health programs.

"No existing client should be left without services as all governments are committed to providing continuity of support for those not eligible for the NDIS," he said.

"The Commonwealth is providing an additional $92.6 million for Continuity of Support."

Disability advocate Kelly Vincent has described the potential job losses as "appalling". ( ABC News: Lauren Waldhuter )

Transition in SA nears completion

As at December 31, more than 15,000 participants had approved plans in South Australia, however the transition of South Australian clients has been taking longer than originally planned.

The NDIA has said they will consider access for South Australian clients unable to be fully transitioned into the new scheme by June 30.

The group has said planning for state clients will be completed by December 31, with Commonwealth clients on track to have their planning completed by June 30, 2019.