A joint appearance from Mr McLachlan and Mr Abdo has led to speculation within the wagering industry that the two executives will support tighter regulations. The sporting codes’ submission to the inquiry recommends no changes be made.

However, during a Melbourne radio interview last week, Mr McLachlan said there was “probably too much” gambling advertising and “it’s in your face”.

“We have a set of restrictions and they are being reviewed at the moment. Probably they will be wound tighter, but we don’t believe in prohibition because all it does is drive it underground or offshore and that has its own set of problems,” he said.

A senior source at the NRL said the organisation was still considering its position ahead of Mr Abdo’s appearance next week.

The inquiry is chaired by Labor MP Peta Murphy, who said she was “pleased” that the two executives had agreed to appear together.

“Since the sport codes made their written submission, we have received substantial evidence contradicting their claim that the current rules around promotion of online sports betting are appropriate,” Ms Murphy said. “This will be their opportunity to tell the committee and the public whether they have considered that evidence and the broader community sentiment.”

Others to appear at the inquiry next Tuesday include former Queensland premier Anna Bligh for the Australian Banking Association and ex-federal cabinet minister Nick Minchin who chairs the industry-group Responsible Wagering Australia.