Thousands of Australians of all ages and backgrounds have gathered around the country today for a National Day of Action to tell Julia Gillard and Tony Abbott it's time Australia had marriage equality.

"Ordinary Australians are giving the Labor and Coalition leaders a strong but positive message that it's time they removed discrimination from the Marriage Act," Greens' human rights spokesperson, Sen. Sarah Hanson-Young, said at the rally in Adelaide.

"Cupid doesn't discriminate in love and neither should our laws. It's time for love and marriage to be equal.

The change of heart by former Victorian Liberal Premier, Jeff Kennett, shows what can happen when people are presented with the facts about why marriage equality matters for young Australians who are coming to terms with their sexuality, the Greens said today.

"Mr Kennett used to oppose letting same-sex couples have the right to choose whether to get married, but he's now a supporter of marriage equality and urges respect for all people," Greens' human rights spokesperson, Sarah Hanson-Young, said.

The Sydney hearing into Senator Sarah Hanson-Young's marriage equality bill has today heard Australia should seize the moment and change the Marriage Act so same-sex couples can have the same legal recognition as heterosexual couples.

"Prominent Australians to Aussie mums and dads have shown overwhelming support for marriage equality, to allow lesbian and gays Australians to marry the person they love in the country they love," Greens' human rights spokesperson, Sarah Hanson-Young, said.

Catholic Cardinal Pell has maintained his marriage sceptic credentials and offended couples who cannot have children in his latest attack removing discrimination from the Marriage Act, the Australian Greens said today.

"Cardinal Pell claims marriage is only to create children, but that remark is a slur on every couple who cannot or choose not to have children," Greens' marriage equality spokesperson, Sen. Sarah Hanson-Young, said.

"By his logic, no person should be permitted to get married if they cannot or choose not to have children.

Tonight's Sydney Mardi Gras is a chance to reflect on the achievements of the past 12 months toward making marriage equality a reality in Australia and ensuring the law is fixed this year, the Australian Greens said.

"Amid all the glitter and glam and happiness on the streets, we should give thanks to everyone helping toward getting discrimination removed from the Marriage Act ," Greens' marriage equality spokesperson, Sen. Sarah Hanson-Young, said.

Greens MP Adam Bandt has welcomed a Parliamentary committee's opening of an online survey into the two Marriage Equality Bills before the House of Representatives.

"I think we will get a fantastic response. There is so much interest in the community. Giving people an easy way to express their views online will be a great thing," Mr Bandt said.

"The previous Senate inquiry was overwhelmed with a record number of submissions, so this is a good way for people's views to be taken into account."

"It's time for equal love supporters to get online."

A new study, to be released in Canberra tonight, shows if same-sex weddings were allowed, they would boost the Australian economy by at least $161 million over three years, the Australian Greens said today.

"Money can't buy love, but these figures show that love can have a favourable economic result for the national budget," Greens' marriage equality spokesperson, Sen. Sarah Hanson-Young, said today.

"This is one stimulus package the government should look favourably on.

Australian Greens Leader Bob Brown, part way through the Senate inquiry into the minerals resource rent tax, spoke to reporters in Canberra today, calling for the mining tax to be extended to gold and uranium.

The anniversary of the Christchurch earthquake, the Greens' move for a Senate inquiry into the draft Murray Darling Basin plan, equal marriage, nuclear submarines, and the Labor leadership saga were also discussed.