The legislation, championed by Greens MLC Tammy Franks, had passed the Upper House and both supporters and opponents expected it to narrowly pass a second reading vote in the Lower House today, which would allow for more detailed debate in committee.

But the conscience vote was decidedly one-sided, with 24 voting against the Bill proceeding, compared to 19 in favour.

Labor MPs from the party’s Right faction played a key role in the result, with all but two MPs affiliated with the Labor Unity group voting to kill the Bill – the only dissenters were former senator Dana Wortley, who was previously a member of the Duncan Left, and Jon Gee, whose AMWU union was similarly previously affiliated with the Left.

First-term Right-aligned frontbencher Jayne Stinson was absent in a pair arrangement with Liberal Nick McBride, and is listed on the pairing form as a vote in favour of the Bill.

A despondent Franks said the result was “somewhat unexpected”, arguing Labor MPs had “played games and let down working people who are criminalised just for doing their job”.

“This is absolute evidence that the Labor Party is the party of Don Farrell not Don Dunstan,” she said, referencing the ALP senator and Right faction powerbroker who held sway over Labor Unity for several years.

Farrell, who was not involved in today’s vote, responded: “I knew Don Dunstan, and he wouldn’t take any notice of what the Greens say about the Labor Party.”

Franks said it was devastating “to have political games played by the current crop of Labor politicians, who refuse to even debate better conditions and remove the criminalised status that puts women in danger every single day in SA”.

Premier Steven Marshall, a leading Liberal moderate, was one who pushed for the reform, telling media before the vote: “I think we need to get it through the second reading”.

“I hope there’s a respectful discussion, [and] I think it’s time for us to move forward and decriminalise sex work in SA,” he said.

“This is not a sector of our community and life that you can stamp out, and at the moment because it’s a criminal activity many women who work in this area feel they cannot go to the police with very serious allegations… this is leaving women in an extraordinarily vulnerable position.

“I think it’s time to deal with this issue – other states have dealt with it, some of them decades and decades ago, and it’s time for SA to move forward.”

But Labor leader Peter Malinauskas, a former convenor of the Right faction, was among those who voted against the legislation.

“If Steven Marshall wants to act on the advice of the Greens, he’s welcome to do that,” he told InDaily.

“I personally will be acting on the advice of my constituents and what I believe is in the best interests of South Australians.”

He said the Labor Party “seeks to represent a cross-section of interests throughout our community, unlike the Greens, who are a minority party”.

“I, as Labor leader, will continue to focus my efforts on ensuring that cross-section of interests is represented in our party, through a conscience vote on this particular issue.”

He said his Croydon electorate was sex-work hot-spot, and he had sounded out constituents before arriving at his own position.

“I answer to them, first and foremost,” he said.

Recently-retired Labor veteran Steph Key was in the members’ gallery with former MP Carolyn Pickles, who she said moved one of the state’s first attempts to decriminalise prostitution back in 1985.

Today’s effort was the 13^th.

Key said Labor MPs were ignoring the wishes of party members, who had voted in support of decriminalising the industry at state convention.

“We’ve consistently over the years at ALP conventions and conferences moved motions that have been supported by ALP members,” she said.

“I’m finding it very hard to understand why people would vote against a second reading, which means you can go into committee and actually nut out issues of concern… the fact a number of ALP members in the House didn’t even support that is very disappointing.”

She said “a lot of the new members in the Labor Party have forgotten – or don’t know – the connection between our state policy platform and their behaviour in the House”.

“We’ll have to remind people of that,” she added.

“I’m very clear that a majority of the Labor movement wants decriminalisation of sex work in SA… I know people have personal views about sex work, but the fact they wouldn’t support even a second reading vote is extremely disappointing.”

Georgia Thain, a campaigner with the Sex Industry Decriminalisation Action Committee and the Sex Industry Network, said it was “extremely disappointing and disheartening that the Bill’s been defeated before it’s even able to be properly debated”.

“It seems a majority of the members in the House of Assembly would prefer to ignore the issues of human and worker rights violations that are going on right now,” she said.

“I’m extremely disappointed that the knee-jerk push against recognising sex workers’ rights has come from the Labor Party – it feels like the party of workers is abandoning us.”

She said it was “very demoralising to sit in the chamber for weeks and hear misinformation and fake statistics used in relation to our work to justify our continued removal of human and worker rights”.

However, she vowed the fight was not over, saying: “We’ll just have to try for the 14^th time.”

Liberal Right-winger Steve Murray was the teller for the No votes, and said “everybody realises there’s a need for reform”.

“This particular model wasn’t the best reform [but] we’re going to look forward to bringing back something which actually prevents the exploitation of women,” he said.

Murray favours the Nordic Model approach to prostitution, which decriminalises sex workers and offers them support for exiting the industry while criminalising those who buy sexual services.

Christian lobby group FamilyVoice Australia spokesman David d’Lima said the result was “a victory for the protection of women and for common sense”.

He added the 24-19 margin and the Bill’s “overwhelming support in the upper house reveal how out-of-touch so many MPs are”.

“Reform of parliament and the political process is greatly needed to ensure anti-family legislation is soundly defeated,” he said in a statement.