Thousands line Melbourne streets for same-sex marriage rally

Record crowds have shown their support for a 'yes' vote in the upcoming marriage equality postal survey at a rally in Melbourne.

Comedians, politicians, celebrities and supporters young and old flocked to the steps of the State Library with rainbow flags and handmade signs today as part of a rally organised by the Equal Love group.

Federal Labor frontbencher Mark Dreyfus said it was just a matter of time until marriage equality is achieved in Australia.

"It's going to happen. It's either going to happen through this process, or whatever process by a private member's bill," he told the crowd.

"This is about all of us as Australians. I know, you know, that voting 'yes' for marriage equality, achieving marriage equality in our country, will make Australia a better country.

"And I'm looking forward to that day."

The rally is an annual event, held to mark the anniversary of the date "the Marriage Act was amended to restrict marriage rights to heterosexual couples", the Facebook event page explains.

This year, it also encourage people to vote “yes” in the upcoming marriage equality postal survey, concluding with a mass same-sex wedding ceremony in a symbolic show of defiance.

Other speakers said the 'yes' movement was buoyed by the addition of 90,000 new voter enrolments since the federal government announced the postal survey.

ACTU secretary Sally McManus said unions had been working across Australia to help people enrol to vote.

"Gay and straight standing together, doing what is necessary to win this important battle," she said.

"We cannot have equality where one part of our human family is denied it."

With AAP.