The Labor Party conference will today consider whether to force its members to vote for same sex marriage.

At the moment Labor MPs have a conscience vote but there is a move from some in the Left faction, including Deputy Leader Tanya Plibersek, to ensure they would be "bound" to vote for marriage equality after the next election.

That would leave those MPs and senators who oppose gay marriage having to abstain or cross the floor, which could see them expelled from the party.

Opponents of the change say denying MPs a conscience vote would make it harder to encourage Prime Minister Tony Abbott to agree to giving his MPs a conscience vote.

The push for a binding vote is set to fail, with some labelling it a "messy" plan because it leaves a conscience vote in place before the next election but then scraps it after that.

One delegate said an issue is either a conscience issue or it is not.

Labor is also expected to change some of its rules today to give party members more say in the way it is run.

Labor leader Bill Shorten called for the party to give its rank-and-file members more power.

But the details of how the so-called democratisation would work are still being figured out, with both issues expected to be discussed during the rules debate this afternoon.

The key issue of the conference was finalised yesterday when delegates accepted Mr Shorten's push for a future Labor government to have the option of turning back boats.

After a passionate and emotional debate the conference voted to reject a motion to ban turn-backs.