Australian Greens Leader Bob Brown today welcomed former Prime Minister Bob Hawke's call for Australia to move ahead towards a republic without delay.

"Labor should be listening to their elder statesman on an issue which means so much to so many Australians," Senator Brown said.

"There can be no reason to delay at least holding a plebiscite on whether or not Australia wants to become a republic."

Senator Brown's Private Member's Bill for a republic plebiscite is before the Parliament and the Senate Inquiry into the Bill is due to report next month.

"Bob Hawke's call for a free vote on the republic plebiscite bill makes a lot of sense and is something I will be pursuing with the Prime Minister," Senator Brown said.