He argued his pro-life stance was one of conviction rather than of political opportunism, drawing massive cheers from a crowd of about 2000 people outside the NSW parliament on a chilly Sydney evening.
"Politically, does this make you popular? No, you'd probably lose half your votes every time you do it. But you know why you do it because that's the right thing to do," he said.
Mr Joyce, who left the Nationals in late 2025, argued that galvanising support around the pro-life cause could change the political landscape.
One Nation has leapfrogged Labor to become the political party with the highest primary vote, according to the latest Redbridge poll.
"I don't know much about a lot, but I know a lot about politics and the one thing politicians fear is losing their job. They're very mindful of that," Mr Joyce said.
"You must keep that fire burning for those people who can't stand up for themselves and I call them people - they're not fetuses."
The demonstration was organised by anti-abortion campaigner Joanna Howe in support of a bill in NSW parliament proposed by Libertarian MP John Ruddick to criminalise gender selective abortions.
Earlier on Tuesday, nurses and midwives descended on state parliament in Brisbane in a showdown over an abortion pill as conservative MP Robbie Katter reopened debate over the controversial topic.
He caused an uproar after indicating he would move to block a healthcare reform that would allow more nurses and midwives to administer abortion medication like MS-2 Step.
Queensland Premier David Crisafulli has put a gag on abortion debate at state parliament after termination of pregnancy laws became a major 2024 election issue.
However, Mr Katter's disallowance motion does not mention abortion, instead targeting updates to the state's Medicines and Poisons framework that allow more nurses and midwives to prescribe medications, including the MS-2 Step early-termination pill.
"MS-2 Step is not a drug for the common cold, or even antibiotics – it's a drug that kills defenceless, unborn children," Mr Katter said in a statement.
Nurses and midwives joined pro-choice supporters on Tuesday accusing him of trying to strip women of practical access to care.
The nurses union's assistant secretary midwifery Fridae King said reproductive health care was ''a right, not a privilege'', warning some women faced driving more than 300 kilometres for services.
''To those politicians who object, I say 'Hands Off Our Healthcare; – women's health is not a bargaining chip, it is a fundamental right,'' she said.
The disallowance motion comes just months after LNP MP Nigel Dalton crossed the floor to vote with the Katter party in a bid to overturn the premier's abortion law debate gag.
Health Minister Tim Nicholls on Tuesday insisted the Liberal National Party government would not change Queensland's termination of pregnancy laws.
He accused the Labor opposition of using the Katter party motion to launch a scare campaign over potential abortion reforms under the LNP.
The state opposition said the abortion issue had driven a wedge through the LNP government "as much as the premier wants it to go away".
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