Nationals senator Matt Canavan says anyone worried about the tone of the debate on same sex marriage should 'grow a spine'.
The National Mental Health Commission warned on Monday it was concerned about the detrimental impact the marriage debate would have on the mental health of people in same sex relationships.
'Can't we just all grow a spine and grow up? The debate hasn't been that bad,' he said.
He said it was time to stop being 'delicate little flowers' and to have a proper debate.
The former resources minister, who stood aside pending High Court proceedings after it was found he was a dual Italian citizen, said the legalising of same sex marriage could also have consequences for Australia's relationship with Indonesia and our other neighbours.
Earlier Deputy Prime Minister Barnaby Joyce said he thought Australians had made up their minds about same sex marriage and the noisy advocacy would not change that.
With survey forms hitting post boxes from Tuesday, the campaigns on both sides of the same sex marriage have ramped up.
Tens of thousands of people rallied in support of marriage equality around the country on Sunday.
Prime Minister Malcolm Turnbull and Opposition Leader Bill Shorten made strong cases in favour of change at campaign launches in Sydney.
'They've made up their mind, they've got it worked out, they're going to send their ballot back,' he told ABC radio on Monday.
Mr Joyce personally wants to keep the existing definition of marriage as being between a man and a woman but will not stand in the way of a 'yes' result when a private bill is put to parliament.
'I just don't want people standing on the corner yelling at me, telling me if I don't agree with them then I'm somehow less than human,' he said.
Mr Turnbull on Sunday made his strongest yet statement pressing the case for the yes vote, saying it was fundamentally a question of fairness.