Peter Dutton, one of the key people in designing the postal survey on same-sex marriage, believes the "yes" camp will prevail.
The Australian Bureau of Statistics revealed on Tuesday that 10 million citizens have had their say, with 62.5 per cent of the voting papers received,..
On Wednesday night, the immigration minister told the audience at a Fairfax Media event in Sydney he believed the "yes" vote would win.
Mr Dutton is personally against changing the law but has pledged to vote for same-sex marriage in parliament if the "yes" vote wins.
There are still four weeks to go before the postal survey closes on November 7.