"I think the Australian people should have their say. I have absolutely no concerns about it myself, but I know there a lot of people who are deeply concerned about the issue," she said.

Julie Bishop has warned travellers of serious consequences if their preparation is inadequate or if they make irresponsible choices while overseas. Credit:Justin McManus

"That's why I think a plebiscite, where the Australian people get to have a vote on it, on an issue as fundamental as this, that goes to the very composition of our community, the way we feel about each other, how we treat each other, that's the core of a plebiscite."

Ms Bishop's comments will give heart to Liberal moderates who are determined, at the very least, to see the reform enacted following a plebiscite of the Australian people but they will anger conservatives in the Liberal Party.

In August, a more cautious Ms Bishop said that she was philosophically a liberal-minded person but that "I'm yet to see the detail of changes to the Marriage Act that would satisfy me that we should vote for it and I've been asking for this for some time".