A Liberal Senator says government MPs who can't in good conscience support same-sex marriage won't be bound by the result of a plebiscite on the issue.
Dumped cabinet minister Eric Abetz has triggered a debate within the coalition over the importance of a plebiscite, which will be held in the next term of government if the coalition is re-elected.
The Tasmanian Senator, who opposes changing the Marriage Act, believes it would be up to each member of parliament to decide whether a plebiscite reflects the view of the people.
The stance has come under fire for pro-change quarters.
Deputy Prime Minister Warren Truss says the results would be carefully considered.
"The vote of the Australian people will be taken very, very seriously by all members of Parliament; of course all members of Parliament have a right to vote as they see fit."