The Greens have announced they will block the same-sex marriage plebiscite-enabling legislation, in a move that could spell the end for the popular vote if Labor also decides to block it.

The Greens join Nick Xenophon and Derryn Hinch in stating they intend to prevent the plebiscite being held, a bloc which would defeat the policy if Labor also decides to block it.

The declaration of the Greens’ position significantly raises the stakes for Labor to make its decision.

Australian Marriage Equality has called for the major parties, Greens and Nick Xenophon to hammer out a deal because it believes no side of politics has the numbers to deliver marriage equality through a plebiscite or parliamentary vote without cooperation.

At a press conference in Melbourne on Friday, leader Richard Di Natale and LGBTIQ spokeswoman Janet Rice announced that the Greens would block the plebiscite-enabling legislation.

On Thursday Liberal MPs including Trevor Evans, Tim Wilson, Russell Broadbent and Craig Kelly warned that a decision to block the marriage equality plebiscite could spell the end of the issue for the next three years.

Rice told Guardian Australia the fastest way to achieve marriage equality was to have a free vote and explained “blocking the plebiscite will increase the pressure on Malcolm Turnbull and the Coalition to catch up with the rest of world”.

She said the Greens had listened to LGBTI Australians who “overwhelmingly have said that if this means no marriage equality until the next term, then that’s a price they’re willing to pay”.

“We don’t accept there should be a delay – there’s a sure fire way to achieve it,” Rice said, in reference to private members’ bills by Labor and the Greens.

On Friday Di Natale told Radio National: “We don’t want a plebiscite – we think a plebiscite is harmful, divisive, expensive.”

On ABC News Breakfast he said the plebiscite was a bad idea and it would unleash hate speech in the community.

“We’ll see young kids harm themselves. I mean, we’re speaking to people in the sector right now who are worried that we’ll see young people take their lives on the back of a hateful and divisive debate in the community.

“It’s expensive and we just don’t think you should be putting issues of fundamental human rights to a popular vote.

“That’s what we’re elected to do as parliamentarians. It should be settled in the parliament.”

Responding to the announcement, Australian Marriage Equality chairman Alex Greenwich called on the prime minister, opposition leader, the Greens and Xenophon to meet before parliament resumes and agree on a pathway for marriage equality.

“No one party has the numbers by themselves to achieve marriage equality through a parliamentary vote or a plebiscite,” he said. “We call on our leaders to urgently come together and deliver marriage equality in line with the wishes of the Australian people.”

Parents and Friends of Lesbians and Gays national spokeswoman Sharyn Faulkner praised the Greens’ decision.

“Our LGBTI children should not have to plead with millions of other Australians to have their fundamental rights recognised, while at the same time enduring hate and bile,” she said.

“Everyday Australian families like mine will be adversely affected by a plebiscite campaign and that’s why we want a free vote instead.”

The opposition leader, Bill Shorten, gave a strong signal at the National Press Club on Wednesday that Labor is positioning to kill the plebiscite, which galvanised the Liberal MPs to warn the opposition that with this it is all or nothing.

Labor has not finalised its position on whether to block the plebiscite. The shadow assistant minister for equality, Terri Butler, has said she would do whatever she can to stop it, and backbench senators Louise Pratt and Lisa Singh have called for the party to block it.

Before the election Shorten said Labor would not accept the Coalition’s “grubby deal” for a plebiscite; after the election and a meeting with the prime minister he said he was “not convinced” about it.

The Liberal MP Trevor Evans said on Thursday there was a “very real prospect” marriage equality would not be delivered for three years or more if the plebiscite was blocked.

The Victorian Liberal MP Russell Broadbent was even more direct. He said if Labor killed the plebiscite there would be no parliamentary vote in this term of government, “and they need to understand clearly that’s the proposition”.

“This issue was put to the Australian people and they are expecting a vote,” Broadbent said.

Craig Kelly expressed a similar sentiment on Sky News. He said Labor had an obligation not to block the plebiscite, which the Coalition took to the 2 July election as its policy.



“If there’s no plebiscite, it is simply off the table for the next three years,” he said.

Kelly’s comments echo a warning from the former prime minister, Tony Abbott, before the election that if the plebiscite was blocked there should not be a parliamentary vote, at least for this term of parliament.