With the future of a national plebiscite on same-sex marriage uncertain, couples continue to face a difficult decision - wed overseas, hold a civil union now or wait for possible change.

Canberra celebrant Sharyn Gunn knows people on both sides of the fence.

"Some of my clients have decided to wait ... Even though it's disruptive to them, to their life, to their wellbeing," she said.

Hayley and Samantha's marriage was annulled just days after their wedding. ( Supplied: Samantha and Hayley Wilson )

"I have done several civil unions this year. They're happy within themselves, and that's very important too."

Same-sex marriage was briefly legislated in the ACT in 2013 but those laws were struck down by the High Court days later.

"For five days it was wonderful, but it was very sad, and it impacted quite a lot when the decision was overturned," Ms Gunn said.

One couple that wed during that time was Samantha and Hayley Wilson.

"It was a really great day, like, we had all our family and friends there, at short notice, the ones who could be there," Hayley said.

After their marriage was annulled, the pair travelled to New Zealand and wed there.

But Hayley said protracted uncertainty had taken its toll.

"The whole waiting side of things, being, is it going to happen, when's it going to happen, it has been quite emotional," she said.

"A lot of our friends are just frustrated."

Timing, nature of plebiscite still unclear

The details of a plebiscite, including the question, public funding and timeframe, have yet to be finalised.

That uncertainty is something opponents of same-sex marriage, like the Australian Christian Lobby's Lyle Shelton, also want resolved.

"There's been very little, almost no consultation with our side, so we look forward to engaging with the Government about the form and nature of the question and how the plebiscite should be conducted," he said.

"What's important is we get it right, and the plebiscite is conducted in a way that's fair to both sides."

The Wilsons have echoed concerns from Labor Leader Bill Shorten, that a plebiscite would be materially harmful to their family, and in particular, their children.

"I just worry about him seeing in print media, or ads on TV, or not even him seeing it directly but his school friends seeing it and questioning him at school," Samantha said.

"I worry about other teenagers who are getting to the stage of realising what their sexual orientation is ... They're in a vulnerable position anyway."

But Mr Shelton said concern from advocates was unfounded.

"This debate's been going on for about 10 years in Australia, there's been no hatred or bigotry coming from our side," he said.

"What's disappointing is the suggestion that if you don't support changing the definition of marriage ... That somehow that position is hatred and bigotry and homophobia."