The prime minister wants some temporary changes made during the coronavirus pandemic to continue beyond their expiry date in September.

"Industrial relations inflexibility in this environment will cost jobs," Mr Morrison told reporters in Canberra on Friday.

Rules around full-time, part-time and casual work, including reducing hours, have been relaxed in some industries during the early stages of the economic crisis.

National cabinet on Friday discussed longer-term changes to industrial laws which will be reformed after employer-union consultations.

Mr Morrison said withdrawing flexibility after September would make it harder for bosses to keep people in jobs.

"If those rigid rules were reinforced - and we talked about this at national cabinet today - then those who are on part-time hours would be most at risk," he said.

"In order to fulfil the requirement of the full-time hours, at the full rates, then I fear that that could lead to part-time employment being lost unnecessarily."

He said women would be particularly affected if part-time and casual jobs were lost.

Australian Associated Press