CANBERRA, Australia — Support for legalizing gay marriage in Australia has weakened just as a national postal ballot asks voters where they stand on the contentious issue, according to a new opinion poll.
The government said Monday it has sent ballots to all of Australia’s more than 16 million voters asking whether the nation should lift its prohibition on same-sex marriage. Results of the balloting that began Sept. 12 will be announced Nov. 15.
A poll by Sydney-based market researcher Galaxy Research published in The Australian newspaper found support for gay marriage had slipped in five weeks from 63 to 57 percent. Opposition had grown from 30 to 34 percent.
The survey of 1,695 voters was taken from Thursday to Sunday. It had a 2.4 percentage point margin of error.
If most of the balloting responses favor same-sex marriage, Parliament will vote within a month on legislation to lift the ban. But some lawmakers have vowed to vote down marriage equality regardless of popular opinion.
If most of the mailed-in responses oppose same-sex marriage, gay rights advocates fear that marriage equality could be off the political agenda for years.
A close result will amplify questions about how accurately the postal ballot reflects popular opinion. Ireland and Australia are the only countries to put the question of gay marriage to the general population; Irish voters overwhelmingly approved in a 2015 referendum.
Market researchers argue that an opinion poll could more accurately gauge Australians’ attitudes at a fraction of the 122 million Australian dollar ($97 million) price tag of the postal ballot.
Reports have emerged of someone marking others’ ballots “no,” stolen ballots being dumped and people attempting to auction their ballots on websites. There are also concerns that shining a torch through the return-envelopes can reveal the vote inside, meaning postal workers could potentially dispose of ballots they disagree with.
Opposition lawmaker Warren Snowdon said someone picked up a bag of mail in the Outback Aboriginal community of Gunbalanya in his Northern Territory electoral division last week and filled out other people’s ballots. In remote communities, letters are not delivered to homes but are collected from a mail center.
Snowdon said a “reputable person” had witnessed the potentially illegal tampering with others’ mail, but did not name that witness. People can fill out others’ ballots, but only if authorized by the addressee.
“It’s not peculiar, I don’t think, to Aboriginal communities in the Northern Territory. I think there is a potential for this to happen across the board,” Snowdon said. “This is absolutely corrupting the process.”
The Australian Bureau of Statistics, which is conducting the postal survey, said it had investigated the Gunbalanya allegation and found no evidence of fraud. The bureau released no details of what its investigation had found.
“The ABS warns Australians theft or tampering with mail is a criminal offence and carries serious penalties,” the bureau said in a statement.
Reports of piles of ballot papers being found in streets of the cities of Canberra and Melbourne have been put down to theft from mail boxes.
Australians who have not received their ballots by Monday can apply for replacements. Each ballot is individually barcoded and mailing a replacement cancels the missing original.
Most of the opinion poll published on Monday was conducted after former Prime Minister Tony Abbott, a vocal “no” vote advocate, said he was head-butted by a “yes” campaigner on Thursday. Both sides of the debate condemned the violence that left Abbott with a swollen lip and his alleged assailant with an assault charge.