A powerful cross-party group of senators have offered their immediate backing to senator Dean Smith's bill, which will be introduced to the Senate on Wednesday afternoon if a "yes" vote is announced in the same-sex marriage postal survey.

BuzzFeed News understands that a motion to introduce the bill will go before the Senate on Wednesday afternoon if a "yes" vote is successful, with debate planned to begin on Thursday morning.

The motion is signed by Smith, along with Liberal senators Linda Reynolds and Jane Hume, Labor's Penny Wong and Louise Pratt, the Greens' Richard Di Natale and Janet Rice, Skye Kakoschke-Moore from the Nick Xenophon Team and Derryn Hinch. Senators are able to add their names to the bill once it is introduced.

The debate on the Smith bill will carry through to the next parliamentary sitting week, beginning on November 27. Any amendments to the bill will be reserved for that sitting week.



The motion also gives a deadline for the passage of the bill by November 30 – then leaving one scheduled sitting week for it to pass the lower house.