A young gay man, who shared vivid memories of being spat on and told he was "no better than a paedophile" while at school, has confronted politicians on the ABC's Q&A panel, asking why Australia's leaders aren't protecting "society's most vulnerable people" amid debate over the same-sex marriage postal survey.

Gordon addressed Nationals senator Matt Canavan — who was joined on the panel by Greens leader Richard Di Natale, Labor MP Amanda Rishworth, Richmond Football Club president Peggy O'Neal and Roy Morgan Research CEO Michele Levine — asking why political leaders were not supporting "society's most vulnerable".

"Mr Canavan, I'm a young gay man who had the misfortune of attending an underprivileged public school," he said. "I endured slurs on a daily basis, was spat upon by more aggressive bullies and found countless numbers of notes stuck in my locker, decrying me as bringing shame to my family or being riddled with AIDS and telling me that I was wasting my life. "I was also told that I was threat to children and that being gay was no better than being a paedophile. "Now you, Mr Canavan, have criticised my community as being delicate little flowers who need to grow a spine in the face of abuse. Isn't the role of leadership to support society's most vulnerable, rather than kick them while they're down in hopes of some political point scoring?"

But Senator Canavan maintained there were "delicate little flowers" on both sides of the debate, and said the core of democracy was to respect views that can be "frustrating and painful".

Key dates in SSM postal survey: August 24 — the final day to register with the AEC if you want to take part in the survey

September 12 — survey forms start being sent out

September 25 — all forms are expected to have been sent

October 27 — forms are strongly encouraged to be returned by this date

November 7 — the final deadline to return surveys

November 15 — results are released

"There is certainly a push from some … the Greens Party have moved motions in the Senate calling those who have a view that support traditional marriage as bigots, and by implication shouldn't be allowed to express that view," he said.

"I've contributed a lot to this debate and tried to do it in a respectful way. It's frustrating when others seek to shut your view down, just because you hold a view."

"Like you did to Westpac when you said Westpac shouldn't have spoken to their employees. You called it same-sex blackmail," interrupted Senator Di Natale, referring to Senator Canavan's comments on the bank sending its staff emails encouraging them to vote yes in the survey.

Senator Canavan denied he had called the note "blackmail", and took aim at Westpac for including a reference in its email which said legalising same-sex marriage would "prevent 3,000 suicides per year". The bank later admitted the figure was a "mistake".

"Let's go with the facts. That particular note you're referring to, they accuse people who … support traditional marriage … of causing 3,000 suicides in Australia every year when last year there was only 2,800 suicides [in Australia in total]. They did so on no evidence whatsoever."

"You're not helping, Matt," Senator Di Natale said, when Senator Canavan's response prompted laughter in the audience.

Ms O'Neal, who is of US descent, said she was disappointed the Government had failed to do its job and decide the matter in Parliament before the national survey.

"Many countries around the world have had it for decades now. The world hasn't stopped. Those countries and their economies and their families have still gone ahead," she said.

"If you see it as more equality — not taking things away from people but giving things to other people — I don't see why it's so difficult, and why we have to have a public debate on it when the politicians are supposed to represent the public anyway."

'Dinosaurs are holding us back on renewables': Di Natale

Sorry, this video has expired The Q&A panel debates the clean energy target

Senator Di Natale and Senator Canavan were also at odds when discussing how electricity prices could be brought down, and who would be left paying for it.

Senator Canavan was adamant renewable energy was not reliable — "so we're left with coal".

"Renewables can't bring more supply. Whatever might happen in the future, right now they don't work all the time. If they were cheaper, then people would be doing it more," he said.

But Senator Di Natale said the energy businesses themselves were sending a message: that the future was in renewables, not coal.

"When Malcolm Turnbull said to AGL, 'We want you to keep open that dirty polluting coal-fired power station for another few years' — the thing that belongs in 1950s Russia — AGL said, 'No, we don't want this thing'," he said.

"Elon Musk says to the South Australian Government, 'We'll build batteries if you, politicians, get out of the way, we'll build one of the biggest battery banks in the world'. And they're on their way of doing it.