Australian Greens Leader Senator Christine Milne is congratulating fellow Tasmanian Rodney Croome on his courageous and persistent activism for gay rights and his long overdue recognition this Australia Day as Tasmania's Australian of the Year.

"I'm incredibly proud of Rodney, who has worked tirelessly for decades to end discrimination," said Senator Milne.

"Rodney and I worked together on my Private Member's Bill in the Tasmanian Parliament in 1997, which took Tasmania from having the worst anti-gay laws in Australia to having the most progressive of the time.

The Australian Greens say the MH17 disaster is a horrific tragedy that will reverberate around the world.

"Our hearts go out to the families and friends of all those who have been killed, especially the 27 Australians reported to be on board," said Greens Leader Senator Christine Milne.

"Tragedies like these always touch many more people than we can ever know, but it is shocking news that up to 108 delegates to the 20th Annual AIDS Conference due to be held in Melbourne this weekend were on board the doomed flight.

The Australian Greens want Prime Minister Tony Abbott to join President Barack Obama and others around the world in condemning new laws in Uganda that outlaw homosexuality with sentences of life imprisonment.

"Tony Abbott has a moral obligation to condemn these horrific laws and to work with the global community to guarantee the safety of all those named as LGBTI in the Ugandan tabloid Red Pepper," Greens Leader Christine Milne said.

The Australian Greens say that the High Court decision today on the ACT's marriage equality laws is incredibly disappointing, but that ending marriage discrimination is inevitable.

"Our hearts go out to the couples married in the last week who will be devastated by today's decision. My message to those couples is this: we will never ever give up until marriage discrimination is a relic of history," Greens Leader Christine Milne said.

Australian Greens Leader Christine Milne says the Abbott government's wasteful move to strike down ACT marriage laws in the High Court will be nothing more than a futile attempt to maintain discrimination against same-sex couples contrary to the wishes of the Australian people.

"The Abbott government should remove marriage discrimination itself and save the States and Territories the effort and cost," Senator Milne said.

"The Greens will be introducing legislation yet again when the Parliament resumes and I invite the PM and Labor to get behind it.

The Australian Greens say Attorney-General George Brandis should release legal advice he says justifies High Court action against ACT marriage equality laws.

"Attorney-General George Brandis should put up or shut up when it comes to the advice that supposedly justifies spending public money on a legal challenge that is all about maintaining last century discrimination," Australian Greens Leader Senator Christine Milne said.

"Tony Abbott's attempt to block same-sex marriage by taking the ACT Government to the High Court will fail because Australians want change and are sick of his last century and discriminatory attitude," Australian Greens Leader Christine Milne said.

"Give up Tony Abbott. You are not going to thwart the will of the Australian people to end marriage discrimination.

"At some point Tony Abbott will have to admit that he supports discrimination against LGBTI people in Australia. It is wrong.

Greens Leader Senator Christine Milne responds to anti-marriage equality ads that are being distributed around electorates:

"This kind of fear mongering is disgusting but it won't have the impact that it might've had twenty years ago. Australians have moved on. We are ready for equality and won't stand for this kind of blatant homophobia," Senator Milne said.

The Greens have a vision of a caring Australia, where every person is able to realise their highest aspirations, free from discrimination in our laws and in our minds.

That's why the Greens have always stood up for full equality for LGBTI Australians, and always will.

It was Christine Milne's Bill that decriminalised homosexuality in Tasmania in 1997, after more than a decade of campaigning and negotiating.