Polls are predicting a win for the ‘Yes’ vote as Australia’s national survey on the definition of marriage draws to a close.

The Australian Bureau of Statistics stopped receiving votes at 4.30pm on Tuesday, bringing an end to a divisive campaign.

The latest nationally representative poll by Essential found 64 per cent of 1792 respondents said they had voted in favour of allowing same-sex couples to marry, compared to 31 per cent who voted against and 5 per cent who declined to answer.

Equality campaign co-chair Alex Greenwich said he was hopeful a majority of Australians had voted in favour of same-sex marriage.

“We’re hoping that on the 15th that we will have a good result for ‘Yes’, but we have to wait and see,” he told The New Daily.

“That hope is based on the experience we’ve had knocking on doors, talking to people right across the country. They tell us two things, that they want to get this done, and that they’ve voting for fairness and equality.”

Australian Christian Lobby managing director says the ‘No’ side is not conceding defeat. Photo: AAP

Lyle Shelton, a spokesman for the Coalition for Marriage, said “millions” of Australians had changed their minds after hearing of the “consequences” of redefining marriage.

“This is the benefit of having a national discussion on an issue of such critical importance,” Mr Shelton told The New Daily in a statement.

“The high turnout shows that Australians recognise the importance of a change to the marriage law, that such a change would have consequences for them, and responded accordingly.”

The ABS said on Tuesday that more than 12.3 million people, or 78.5 per cent of eligible votes, had participated in the postal survey – a participation rate surpassing the recent US election (55.5 per cent), the Irish same-sex marriage referendum (60 per cent), and the Brexit vote (72.2 per cent).

The agency said an extra 300,000 votes were received last week.

If Australians vote for same-sex marriage, the Coalition for Marriage will “keep fighting,” Mr Shelton said.

“The ‘Yes’ campaign has already said it will not accept a ‘no’ vote, so if our campaign prevails, then we will still need to do what we can to protect parental rights, freedom of speech and freedom of belief. It’s straight back to work for us either way.”

While the latest Essential poll reflected the result of most other polls showing a winning ‘Yes’ vote, a recent academic study of social media site Twitter contradicted those results.

Griffith University professors David Tuffley and Bela Stantic used advanced data analytics which they say have proven accurate at predicting the outcomes of hard-to-call polls, including the 2016 US presidential election. After running their algorithms, support for yes came in at only 49 per cent.

The ‘Yes’ campaign has been well supported by a number of high-profile Australians, including Prime Minister Malcolm Turnbull and Labor leader Bill Shorten while former prime ministers Tony Abbott and John Howard have been prominent ‘No’ advocates.

The ABS will announce the results on Wednesday, November 15 in a nationally televised press conference scheduled for 10am at the agency’s headquarters in Canberra.

If the ‘Yes’ vote wins, the government will facilitate a free parliamentary vote on WA Liberal senator Dean Smith’s private members’ bill to legislate same-sex marriage.