By Agence France-Presse
Almost 62 percent of the 12.7 million people who participated in the two-month postal survey voted in favour of allowing gay marriage, the Australian Bureau of Statistics announced at a press conference in Canberra. The "no" vote garnered 38.4 percent.
Nearly 80 percent of eligible voters took part in the poll, said the chief of the statistics bureau Davis Kalisch, adding: "Australians can have confidence these statistics reflect the view of the eligible population."
Same-sex couples could be able to marry by Christmas, but first parliament must adopt legislation giving the non-binding vote result the force of law.
Thousands of marriage equality supporters erupted into celebrations at rallies in major cities across Australia when the result was announced.
"This means everything, this means everything," repeated Chris, fighting back tears and hugging his partner Victor at a huge rally in Sydney.
- "Yes for love" -
Prime Minister Malcolm Turnbull, a moderate conservative who supported legalisation, called the "yes" vote an "overwhelming" endorsement of marriage equality.
"They (Australians) have spoken in their millions and they have voted overwhelmingly yes for marriage equality," Turnbull told reporters in Canberra.
"They voted yes for fairness, yes for commitment, yes for love."
He reaffirmed that his government would now push ahead with passing legislation to change the marriage laws by Christmas.
Turnbull defended the ballot's legitimacy, and said he was confident of pushing the issue through parliament in a "conscience vote" where lawmakers are not obliged to vote along party lines.
But he must first battle hardline elements within his own ruling coalition who have demanded extensive "religious freedom" exemptions that would roll back discrimination laws.
This include allowing commercial service providers to reject same-sex weddings and let parents pull their children from school programmes they feel undermine heterosexual traditions.
Turnbull and the opposition Labor Party have backed a simpler draft bill that legalises gay marriage while allowing religious institutions to refuse to wed same-sex couples if they oppose the practice.
That bill is expected to be introduced in the Senate as early as Thursday.
A survey of federal politicians by the Australian Broadcasting Corporation published Tuesday found that 72 percent of the lower House of Representatives would support changes to marriage laws and in the Senate, 69 percent would approve the changes.
Wednesday's result was a historic accomplishment for proponents of marriage equality after more than a decade of political wrangling and two months of voting, which highlighted deep divisions in Australian society over the issue.
"Yes" campaigners complained gay people and their families were subjected to hate speech, while "no" supporters argued they were being accused of being bigots for not favouring such unions.
Even before the ballot papers were sent out in September, the debate turned toxic with a poster emblazoned "stop the fags" put up in central Melbourne and flyers describing homosexuality as "a curse of death" distributed in suburban Sydney.
Amid public outcry over the hostile discourse, the government had to rush through legalisation to introduce safeguards during the campaign process, including tighter advertising restrictions.
Conservative opponents vowed before Wednesday's result was announced to pursue their campaign for exemptions from the eventual legalisation of gay marriage, which they say will lead to attacks on their freedoms of speech and religion.
"If a 'yes' vote is returned, we will do what we can to guard against restrictions on freedom of speech and freedom of religion, to defend parents' rights, and to protect Australian kids from being exposed to radical LGBTIQ sex and gender education in the classrooms," Lyle Shelton, a spokesman for the Coalition for Marriage, said at the weekend.
"We promise our supporters that no matter the result, we will continue to work to defend Australian families," he said.