"It's not good enough, it could have been done yesterday (with a vote in Parliament)", she said. This time the split is part of a wider internal schism. It's about your view.
Paula Gerber, deputy director of the Castan Center for Human Rights Law at Monash University in Melbourne, said she did not know of another country that had sought such an advisory vote. He urged them to enrol to vote and to encourage others to do so.
Voting "no" would "stop political correctness in its tracks".
The Australian Christian Lobby (ACL) warned that redefining marriage is the precursor to "redefining gender" and could threaten religious freedom. The legislation was introduced by the government but voted down by the Labour opposition, the Greens and Nick Xenophon Team (NXT), who claimed the public vote at more than 120 million Australian dollars ($95 million) was an expensive waste of time.
A challenge was announced on Wednesday by independent MP Andrew Wilkie and gay activists.
The opposition accuses Mr Turnbull, who must face the right wing of his own conservative party, very hostile to gay marriage, wanting to "pass the hot potato to the people", without defending LGBT rights, according to the terms of senator Penny Wong.
Australia House, where more than 15,000 ballots were cast in the 2013 election, has had a "handful of inquiries" from Australians asking how they can cast their vote in the same-sex marriage plebiscite, says Prue Loney, communications adviser for the Australian high commission.
Mr Shorten slammed the government for delaying the issue which could be sorted out "in five minutes" if the Liberal Party allowed a free vote.
"It's just something we've never done in our constitutional arrangements of Australia, and it really is unacceptable", Kirby told Australian Broadcasting Corp.
Both applications questioned the legal validity of the postal plebiscite, arguing the expenditure of $122 million for the vote is not constitutionally valid because it hasn't been approved by parliament.
Regardless of whether we should be having the postal ballot, it's clear the campaign will see some bare-knuckled brawling. I think some of the issues that have been raised about issues like religious freedom, we've seen in other parts of the world that when we do redefine marriage that religions, Christians and others, can find it hard.
Ms Forster has sparred with her brother in public before.
Forster said her brother was just "plain wrong" in his negative stance on same-sex marriage.
"It's one big opinion survey to get over the fact the Liberal party room can't make a decision, so they're so divided and because regrettably, Malcolm Turnbull hasn't had the courage of conviction".