A new poll has found that only 48% of Australians back a marriage equality plebiscite, casting doubt over the government’s claim the “overwhelming majority” of Australians back the idea.

Galaxy asked 1,000 Australian voters “regardless of your views on same-sex marriage” whether they support or oppose a national plebiscite to decide whether same-sex couples should be able to marry.

The poll, commissioned by the Parents and Friends of Lesbians and Gays (PFLAG), found 48% of respondents supported the plebiscite, 30% oppose it and 20% are undecided.

When told the result of a plebiscite would not be binding and “politicians will still need to vote on whether to agree or disagree with what the public has decided, potentially overriding the public’s vote”, support fell to 33%.

When told the plebiscite is expected to cost $160m, support came in at 25%.

The results are slightly higher than a Centre for Applied Political Psychology (Capp) poll in June, which found 40.4% supported a plebiscite.

On ABC’s 7:30 on 8 June, the prime minister, Malcolm Turnbull, said “there is overwhelming support in the community for the plebiscite”.

“People actually quite like the idea of having their own say in it.”

PFLAG national spokeswoman, Shelley Argent, said: “The government must heed the Australian public by dropping its plan for a costly, damaging and pointless plebiscite and allowing a free vote in parliament asap.”

“The Australian public just voted for a new parliament in which a majority of members support marriage equality.”

Australian Marriage Equality national director, Rodney Croome, said: “Support for a plebiscite has fallen dramatically since it was first mooted in August last year and about 70% of the public backed the idea.

“I attribute this to the public being made aware of how costly, unnecessary and damaging it will be,” he said.



“To avoid a plebiscite, marriage equality advocates must continue to educate the public about how a free vote in parliament is the most appropriate and effective way forward.”

Coalition MPs who claim majority support cite a Griffith University poll which found that 70% of Australians want the people to have a direct say in the issue of marriage equality.

Marriage equality researcher from the University of Queensland, Sharon Dane, has questioned that result “because the question was not specific to the issue of allowing same-sex couples to marry”.

Argent claims that Coalition MPs have wrongly described the Capp poll as “push polling” because it also asked questions which included the cost and nonbinding nature of a plebiscite.

But an independent assessment of the polling data prepared for Capp by University of Melbourne senior research fellow Denis Muller found the question which showed 40% support for a plebiscite was “unexceptional” and “does not contain any element of push polling”.

Asked about the poll on Radio National on Thursday, the deputy Nationals leader, Fiona Nash, said she would continue to back a plebiscite.

“We think the best way to address this issue is to give the people a say,” she said.

Nash committed to vote in line with the result of the plebiscite when marriage equality was voted on in the parliament.

On Monday Turnbull said he would bring legislation to enable a plebiscite as soon as practicable, but the plebiscite may be held in early 2017 rather than this year as he had previously planned.