Since starting work at the Woolworths supermarket warehouse in Yennora seven years ago, Ms Dimovska has been hoping her casual job would become permanent.

"I am thrilled to be permanent starting on Monday," she said.

As a 45-year-old mother of three, Ms Dimovska is looking forward to having greater job security and certainty in her working hours and entitlements.

The National Union of Workers helped the 13 casual positions become permanent through a memorandum of understanding with the company.

Ms Dimovska said it would be easier to plan her holidays and family activities around her regular working hours.

The Australian Council of Trade Unions is preparing a submission to the Fair Work Commission to give more workers the right to become permanent employees.

It wants a clause introduced into modern awards allowing casuals to become permanent

Australian Industry Group chief executive Innes Willox said his organisation was "vigorously opposed" to the unions' casual employment claims because they were not in the interest of employers who depended on flexible workplaces.

A spokesman for Employment Minister Eric Abetz said: "We won't be providing any commentary while there is currently a review being undertaken."

John Buchanan, director of University of Sydney's workplace research centre, said the ACTU claim was positive, but more needed to be done to prevent the deterioration of conditions for all workers.

He said the 20 per cent casualisation rate had settled, but the quality of permanent jobs had deteriorated.

"A permanent job now is not nearly as secure as it was 20 or 30 years ago," he said.

"One of the reasons casual employment hasn't increased is because of rising levels of involuntary part-time work.

"Casual workers do need protection. Employers are deeming their workforce to be casual so they can evade the labour entitlements that normally accrue."

Professor Buchanan said the bigger question to be answered was how to achieve quality labour standards for the entire workforce, including permanent employees.

"I think the big challenge is how do you get forms of employment where you can get both flexibility and security," he said.

"The best examples are ethical labour hire companies or better group training companies where you get continuity of employment and rights that go with that spread across employers."