Whether your leave a tick in the yes or no boxes is a decision only you, the voter, can make.

But not doing anything, by leaving the form pinned to the fridge or forgotten under a pile of papers, by not posting that prepaid envelope and form is just sheer apathy.

Similar to those who don’t vote during a local government, state or federal election, apathy on such an important – and divisive – issue is not helping the debate.

And it’s also a waste of time and our hard-earned taxpayer money, with the survey costing more than $100 million to undertake.

According to a senior politician, apathy is the biggest threat to the same-sex marriage debate.

Acting Labor leader Tanya Plibersek said while campaigns on both sides of the argument have been ramped up, the difficulty now would be making sure people actually returned their forms.

"I think that the biggest threat … is people assuming that this is in the bag …. and they think, 'well, my vote won't matter," Ms Plibersek said on Sunday.

"Apathy is the biggest risk here."

But it doesn’t matter whether you are on the anti or pro-same sex marriage campaign side, not participating in the survey is not helping the issue which has divided the nation.

And Cabinet minister Greg Hunt, who supports marriage equality, was optimistic about the process but still sounded a caution.

"Nobody should ever presume an electoral outcome and if you do, whether it's the Australian people or others in a democracy, they don't like being taken for granted," he said.

We live in a democracy, where we can exercise our right to free speech. Let’s use that democracy to cast a vote – either way.

But don’t waste our time and money by sitting on your hands and doing nothing. Fill out your survey form and post it.

The Bureau of Statistics advises anyone yet to receive a form by late on Monday to contact them.

Telephone and online responses also open Monday.

The result of the voluntary postal survey on same-sex marriage is due on November 15.