The Attorney-General's Department has been approached for legal advice on conducting a postal vote on same-sex marriage.
Cabinet minister Peter Dutton has confirmed he is investigating a postal vote on changing the Marriage Act after a regular plebiscite was sunk by parliament.
Senior officials from the Attorney-General's Department, appearing before a Senate inquiry on Friday, confirmed they had been consulted about carrying out such a task.
The request for advice from the Finance Department, who is responsible for the Australian Electoral Commission, came after the plebiscite legislation was rejected by the Senate in November.
"Part of the consultation, senator, has been to seek legal advice from us," Iain Anderson from the Attorney-General's Department told the hearing in Canberra.
The Attorney-General's Department was not asked to calculate the cost of a postal vote and did not consider the legal or constitutional validity of changing legislation based on its outcome.
"We haven't independently turned our mind to those issues," Mr Anderson said.
Mr Dutton said on Thursday he and others in the Turnbull government are working to find a sensible resolution to the issue of gay marriage during this term of parliament.
It was clear parliament would not pass legislation required to trigger a regular plebiscite, and the postal alternative would require no such laws.
Labor leader Bill Shorten questioned who dreamed up the non-binding postal vote, which he said was nothing more than an opinion poll.
The opposition leader bemoaned the issue becoming a political football, saying politicians should vote on the issue and be done with it.
Former prime minister Tony Abbott said the Liberal Party's commitment remained that the Marriage Act would not be changed without "being put to the people first" in a referendum-like vote.
Mr Abbott said he respected Mr Dutton and was confident the minister was trying to secure "the best possible way of realising the commitment" the Liberal Party took to the 2016 election.
