Shorten to press for penalty rates to stay

Opposition Leader Bill Shorten says he'll make a submission to the Fair Work Commission calling for Sunday penalty rates to stay if he becomes prime minister.

Mr Shorten said at the leaders' Facebook debate Labor was committed to defending penalty rates which were not an unfair burden on the system.

Prime Minister Malcolm Turnbull said it was not the government's role to be intervening in Commission considerations.

"That's a matter for the independent umpire and we believe the independent umpire should be independent and not be leant on by government one way or the other," he said.