Western Australia’s gender identity laws are being called into question after the Cook government mounted a legal bid to stop an inmate who has transitioned to female while incarcerated in a men’s prison from transferring to a women’s jail.

The government’s legal action came after the State Administrative Tribunal recently ruled in favour of the inmate’s move, and is set to go before the WA Supreme Court on Friday afternoon.

One Nation’s WA leader Rod Caddies said his party had previously warned that giving male offenders the legal right to be recognised as female could create dangerous situations in women‑only spaces, including in prisons.

But WA Greens women and children’s safety spokesperson Jess Beckerling backed the SAT’s determination, and said it would have been based on a thorough understanding of the broader safety considerations.

A suppression order is in place, preventing the inmate known as “SD” from being identified due to concerns for their safety in the men’s prison.

Prominent Perth King’s Counsel Tom Percy told 6PR on Friday that the SAT ruling would be a significant issue for the government.

“You can imagine what sort of problems it’s going to create for the government if that’s allowed, where does it end?” he said.

“All sorts of people will start transitioning inside male prisons so they can get to female prisons.”

A government spokesperson said the safety of staff and prisoners was the priority under the Department of Justice’s appeal against the SAT decision.

“It would be inappropriate to comment further while the matter is before the courts,” they said.

Last year, new laws allowing a streamlined process for sex or gender recognition for trans and gender-diverse West Australians came into effect in May.

The legislation allows individuals to apply directly to the Registry of Births, Deaths and Marriages to update their sex or gender on their birth registration record.

However, it is understood that the prisoner in question used a gender recognition certificate issued under the now-replaced Gender Reassignment Act to change the sex on their birth certificate.

Caddies claimed the state government’s gender self‑identification laws were now colliding with basic community safety.

“When the Cook Labor government rammed through its gender self‑ID bill, anyone who raised obvious safety concerns was smeared as a bigot and a hater,” he said.

“Now we see the Cook government rushing to court to stop another trans‑identified male from being moved to a woman’s prison in an eleventh‑hour emergency bid.

“By the letter of that law, that person has a Labor‑created ‘right’ to be held in a women’s prison, and anti‑discrimination provisions will be weaponised to demand exactly that.”

Beckerling said it was unacceptable for the government to have intervened to try and overturn the SAT decision.

“We know that this woman is extremely unsafe in [the men’s prison], and she deserves to be safe,” she said.

“At the end of the day, prisons in Western Australia are not safe places because of mismanagement and overcrowding.

“The Cook Labor government should be focusing on this and keeping all inmates safe.”

Caddies tied the government’s intervention to the looming byelection in Secret Harbour, where Labor is widely tipped to face a challenge from One Nation, claiming the premier was “terrified of the backlash in the middle”.

However, Beckerling accused One Nation of using the case to whip up transphobia, which she said was disgraceful and must be called out.

“Let’s not pretend for a second that One Nation cares about women,” she said.

“This is about transphobia and dog whistling.”