Nick Jensen and his wife Sarah announced they would divorce - legally speaking - if same sex marriage becomes law

A Christian couple will likely face awkward questions after the postal survey results are announced tomorrow - given they once pledged to divorce if gay marriage is legalised.

Husband and wife Nick and Sarah Jensen sparked controversy in 2015 when Mr Jensen announced they would end their decade-long legal union if gay marriage becomes law.

'This has been a big decision for my wife and I,' Mr Jensen wrote for Canberra's CityNews. 'The truth is, "marriage" is simply too important...

'It has always been understood to be that exclusive relationship where one man and one woman become "one flesh".

'Any attempt to change the definition of marriage by law is not something in which we are able to partake''.

So - with polls predicting a commanding victory for the 'Yes' campaign on Wednesday - what's next for the Jensens?

The couple haven't played a prominent role in the 'No' campaign - although Mr Jensen did decorate his Facebook profile picture with this political sticker

'The only woman I have ever loved': Mr Jensen announced in 2015 the couple will refuse to recognise Australian marriage law if same sex marriage is legalised

Contacted this week, Mr Jensen said the couple will wait to see what any change to the marriage law is before publicly announcing their future plans.

'We just need to see the legislation and if it all goes that way,' he said.

'....Then we know what situation we're in and what we're going to do.'

He was coy about specifics and laughed when asked if he was feeling nervous about the vote.

Despite his fame, Mr Jensen - who previously worked for the Australian Christian Lobby - hasn't been on the front lines of the No campaign.

'Our situation is a bit of a unique one from the rest of the No campaigners,'he said.

'In part, we're affected if there is a bit of a change in law - I haven't been out there on the front line campaigning.'

In his 2015 piece, Mr Jensen said he and his wife - 'the only woman I have ever loved' - will still live together and call each other 'husband and wife' - in the 'eyes of God'.

But he wrote they would 'refuse to recognise' the government's marriage regulations 'if its definition includes the solemnisation of same sex couples'.

Mr Jensen's column sparked such a reaction that more than 100,000 people signed up to attend a Facebook event, 'Celebrating Nick and Sarah Jensen's divorce'.

Close to 80 per cent of all Australian voters returned their postal surveys during the campaign

Same sex marriage supporters are hopeful the vote will fall their way (demonstrators are pictured during a rally in Melbourne)

'You can say no': The No campaign pinned its hopes on this slogan and concerns about the ramifications of a new law

But his piece quickly led to questions about whether the couple could legally divorce without separating for the years - as is required by federal law.

In the years since the opinion piece, the couple haven't made any announcement signalling they had changed their minds.

Australian Bureau of Statistics boss David Kalish will announce the result of the postal survey about 10am on Wednesday.

If Yes, Prime Minister Malcolm Turnbull has said a bill will pass the Parliament by Christmas.

A Newspoll published on Wednesday found 63 per cent support for same sex marriage after the conclusion of the campaign.