A new bill that would require South Australians seeking an abortion from 28 weeks to give birth has been denounced as tantamount to “forced birth” by the Greens, while the lead standards body in women’s health called it an attempt to limit healthcare access.

The bill was introduced into state parliament on Wednesday by Liberal frontbencher Ben Hood, though it is not Liberal policy and is unlikely to pass both houses to become law.

Under the existing legislation, abortions after 22 weeks and six days are allowed in extreme circumstances where there is significant risk to mother or foetus. Under the proposed legislation, a woman needing an abortion after 27 weeks and six days would have to either keep the baby or adopt it out.

Hood argued the bill would not remove a woman’s right to end a pregnancy, because the pregnancy would end when the baby was born.

“If a pregnancy must be ended, it requires that the baby be delivered alive,” he said.

“The bill ensures that the mother’s decision to end her pregnancy is respected, but also that the child has an opportunity to live.

“In fact, the innovation of this bill is that it allows a mother to end her pregnancy throughout all nine months and indeed, right up to birth.”

The Liberal party will allow a conscience vote on the matter.

Abortions were decriminalised in SA in 2021, and those reforms included the 22 weeks and six days’ threshold and the conditions under which they occurred.

Hood claimed 45 abortions had occurred after that threshold.

SA Health data shows that in 2023, fewer than 1% of terminations (47) were performed after that stage, but fewer than five were performed after 27 weeks.

Hood claimed those foetuses were “healthy, viable babies” and “individual unrepeatable human lives”.

“Of these 47 terminations, 37 were conducted for the physical or mental health of the mother, and 10 were for fetal anomalies,” SA Health said in a statement.

“In the first 18 months after the legislation was implemented, there were less than five terminations performed after 27 weeks and no terminations after 29 weeks.”

Greens MLC Tammy Franks said later abortions were “very complex, often heartbreaking cases” and that “playing politics with healthcare is dangerous folly”.

“His proposal would force birth upon children; victims of rape, incest and sexual slavery; or on much wanted pregnancies where the mother or the foetus will not survive his forced-birth plans for them,” she said.

“The SA Greens stand firmly against attempts to roll back hard-won reproductive rights. We will continue to fight for policies that ensure access to comprehensive healthcare, including reproductive services, without fear or stigma.”

Hood thanked anti-abortion activist Joanna Howe for her work on the bill. Howe has been pushing nationally for “born alive” bills and wants “an Australia where abortion is unthinkable” and is a labour migration specialist and law professor at the University of Adelaide.

Gillian Gibson, the president of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, said abortion was “an essential healthcare service”.

“A decision to terminate a pregnancy should be a discussion between women and their doctors,” she said.

“Any attempt to further legislate abortion is an attempt to deny women access to health care.”

The SA Liberal leader, Vincent Tarzia, told ABC radio the proposal was not party policy but that Hood was a “rising star”. Conservative SA senator Alex Antic has previously called him the “Ron DeSantis of South Australia”.