Prime Minister Malcolm Turnbull has encouraged people to complete the same-sex marriage survey.
The Australian Bureau of Statistics has started the progressive delivery of Australian Marriage Law Postal Survey materials to more than 16 million eligible Australians.
About half of the postal surveys have been delivered with the remainder expected to arrive by the end of the week.
The packages contain the survey form, a reply paid envelope and survey instructions.
The survey is collecting views on whether the law should be changed to allow same-sex couples to marry.
The Prime Minister urged people to fill in the survey
“Lucy and I will be voting yes,” he said.
“We encourage others to do so but respect absolutely the right of those to take a different view and respect their different view, but above all, have your say.”
Campaigns for both sides of the debate are under way.
Campaigners against same-sex marriage took their message to the sky over Sydney on September 17.
The Prime Minister said people were entitled to express their views.
“If you want people to respect your point of view, you have got to be prepared to respect theirs,” he said.
The postal survey came after the federal government was unable to get Senate support for a plebiscite.
Detailed information about the survey is available from www.marriagesurvey.abs.gov.au or by calling the information line on 1800 572 113 from 8am to 8pm, seven days a week.
Requests for a replacement form open on September 25 and close on October 20.
All eligible Australians are encouraged to return their survey form straight away.
The Port News gauged readers’ thoughts about same-sex marriage.
A Port News poll asked: How will you vote in the same-sex marriage survey?
Of the 322 votes collected, 67.08% voted yes, 30.43% voted no, 1.55% indicated they would not participate and 0.93% didn't care.