In a marriage equality debate where some often argue "think of the children", it's often instructive to ask the children what they actually think.

Corin Nichols Tomlins and his sisters Scout and Cully share pretty firm views. The first is that having two mums is "normal and awesome". The second is that a plebiscite could cause immense harm – or as Corin told a marriage equality rally in Melbourne on Saturday: "it's like giving people money to insult us."

"I really don't think a plebiscite is a good idea, because it's an excuse for people to say nasty things about my family," says the 13-year-old history buff. "I want people to actually listen to the children instead of using us as an argument."

It's a view that Corin and his siblings have expressed before – most recently to federal MPs during a Rainbow Families road trip to Canberra last month as the debate on same-sex marriage intensified.

But the question of a plebiscite will come to a head this week when Labor's shadow cabinet formalises its stance on Monday, with Opposition Leader Bill Shorten widely expected to confirm the party will not support a public vote.

Whether a compromise can be found remains unclear, although the push for a free vote intensified at the weekend when leading law firms Baker & McKenzie, Marque Lawyers, Maurice Blackburn and Squire Patton Boggs became the first in the country to openly encourage the Turnbull government to dump the plebiscite in favour of legislation to amend the Marriage Act.

Mental health services also warned that the broader debate has already led to an explosion in the number of LGBTI people seeking help for psychological distress.

Drummond Street Services chief executive Karen Field told Saturday's rally that her organisation's Queerspace mental health service had received a two-fold increase across all age groups seeking support.

"Despite Queerspace supporting 428 LGBTIQ people in the previous year, this has blown out to over 700 people in the last 12 months," she said. "How about we spend money for mental health support for this community, not divisive hate platforms?"

As for the kids? They tend to think that federal Parliament should just get on with it. After all, what's the big deal?

"None of my friends care that I have two mums, and sometimes kids actually say having two mums is really cool," Cully Nichols Tomlins, aged 9, told the crowd.

"I think it's unfair that people say 'think of the children, they need a mother and father' but they don't really care about us. We are the same as any other family but they just ignore that."

Her sister Scout, 11, put it like this: "I saw a picture on Instagram that said God wouldn't discriminate, so why do some people who believe in God discriminate against my family?"

Sometimes the young ones make the most sense.

Source: The Age