Roundup: Australia's PM denies his party members a conscience vote on marriage equality

Australia's Prime Minister Tony Abbott has come under fire, this time from his own family, after disallowing a conscience vote within his party on the issue of marriage equality should a bill be introduced to parliament next week.

Late on Tuesday, Abbott told reporters the government would continue to defend "traditional" marriage throughout his term at the helm, but kept the option of taking a vote to the people at the next election.

The result was decided after a six-hour partyroom debate in Canberra.

However, his own sister, Christine Foster, told the Australian Broadcasting Corporation (ABC) that it was "not the right result" and that she, as an openly gay woman, was "very disappointed".

She claimed Abbott had begun to stray away from the core values of the Liberal Party, which was founded on the premise that everyone was equal.

"Look, I'm feeling very disappointed. And, you know, I fervently wish that the vote had gone the other way," she told the Lateline program on Tuesday evening, following the announcement.

"Obviously for me, as a Liberal, it also goes to the core of my values as a Liberal, which is that, you know, human beings should be equal before the law."

Up to three-quarters of all Australians support gay marriage, and Foster said Abbott's decision to block a free vote was not reflective of the democracy he represents, rather, his own values.

"That's a pretty strong reflection (of the party's opposition) but unfortunately it actually reflects in almost opposite fashion what the polls will say, the Australian people believe about this issue."

According to Fairfax Media, Abbott's decision to employ "tricky tactics" ensured the Liberal MPs would not be allowed to vote freely on the issue.

Fairfax alleged Abbott did not consult his cabinet or his party before taking his position to a joint meeting with the Liberal Party's coalition partner the Nationals.

On Wednesday morning, Abbott confirmed the news to the ABC, reminding his sitting frontbenchers that if they decided to "cross the floor" and vote against party policy, they would be fired.

"(It's) the standard position of our party that if a frontbencher cannot support the party's policy, that person has to leave the frontbench."

"That has always been our position."

Should a conscience vote eventually be approved by the prime minister, marriage equality is more likely to pass in the lower house as many high-ranking Liberal MPs, including Communications Minister and former Opposition Leader Malcolm Turnbull, are in favor of at least a conscience vote.

Assistant Treasurer John Frydenberg has been on record as saying the refusal to consider a conscience vote worked against the spirit of the party's founder, former Prime Minister Robert Menzies.

Meanwhile, Opposition Leader Bill Shorten was quick to return fire at Abbott, claiming that under his leadership, he would never allow a marriage equality bill to pass.

Shorten said if Labor was elected at the next election, it would introduce a bill in favor of marriage equality "within 100 days."

"When it comes time, if (Abbott) gets re-elected at the next election, you can forget about marriage equality," he said on Wednesday.

"The choices in this country -- you either have Mr Abbott or you have marriage equality, but you can't have both.

"Labor will introduce a bill for marriage equality and I am confident if we win the election, there will be sufficient votes in this country to finally remove discrimination against people." Endi