Christopher Pyne and Malcolm Turnbull have taken a public but silent stand on same-sex marriage, as the only two ministers to sit on the frontbench as Warren Entsch introduced his long-awaited cross-party bill.

As Mr Entsch introduced his bill on same-sex marriage to the House of Representatives, Prime Minister Tony Abbott said the Coalition's policy on how a national vote would work would be sorted "in the next couple of weeks".

Ahead of a cabinet meeting on Monday, which is expected to discuss having a plebiscite or referendum on same-sex marriage, Mr Entsch spoke to a near-empty government side of the chamber.