NSW waits on feds' disability inquiry call

Australia's most populous state says it's yet to hear from the prime minister about a proposed royal commission into disability services.

But NSW Minister for Disability Services Ray Williams says the state is "very, very firmly on board" for an inquiry after Scott Morrison warned it couldn't go ahead unless the states and territories are "all in".

"I'm a great believer that if you want to address neglect abuse or harm on behalf of anybody but especially the most vulnerable members of our community, that you need to shine a very, very direct light," he told ABC Radio on Wednesday.