Scotland’s prison service has abandoned Nicola Sturgeon’s self-identification policy, announcing that it would base decisions on where to send new prisoners entirely on their biological sex.

In a major climbdown following the scandal of a transgender rapist being placed in a female jail, the Scottish Prison Service (SPS) said it would disregard a prisoner’s gender identity when making initial decisions about whether to send them to a male or female jail.

The shift marks a major reversal of previous prison service policy in Scotland, which was heavily influenced by trans activists and prioritised “social gender” over biological sex.

Trans prisoners in Scotland had previously been told they would be “allocated” based on their gender identity after being convicted or remanded.

It moves the regime for managing trans prisoners north of the border closer to the system in England, where ministerial approval is needed to send trans women to female jails in most cases.

The reversal also dealt a further blow to Ms Sturgeon’s push to allow Scots to change their legal gender without providing any evidence.

The law, passed at Holyrood in December, was vetoed by the UK Government because of fears it would put women and girls in danger and be exploited by sexual predators.

The SPS was already reviewing its policy, designed so that trans prisoners could be their “authentic selves”, but a series of interim measures was announced on Thursday following the Isla Bryson scandal.

Keith Brown, Ms Sturgeon’s justice secretary, published a short summary of the events that saw Bryson, who was previously known as Adam Graham, being transported to the Cornton Vale women’s jail last month after being convicted of two rapes.

Mr Brown said Bryson came into contact with no female inmates, but Ms Sturgeon was accused of presiding over a “whitewash” by refusing to publish the full report into the case because of fears over compromising the rapist’s “personal data”.

While it is still possible that a trans woman would be sent from a male to female jail following a risk assessment, the SPS said it would place greater emphasis on a criminal’s “previous offending history”.

All cases in which trans women are currently in female jails or prison wings in Scotland are currently being reviewed.

Russell Findlay, the community safety spokesman for the Scottish Tories, described the U-turn as “extraordinary”, claiming it “appears to turn the existing trans prisoner policy on its head, effectively abandoning the principle of self-ID”.

“Keith Brown seems to be making it up as he goes along, changing the rules in response to every new headline,” said Mr Findlay. “Days ago, he said violent male-born prisoners would not be sent to women’s prisons. Now the SPS seem to be saying that all male-born prisoners will be banned.”

Attacking the SNP’s refusal to release the full report, he added: “This is typical of SNP secrecy and raises more questions than answers. 

It is clear that this shoddy stunt is part of the ongoing exercise in damage limitation for Nicola Sturgeon, not a sincere attempt to learn lessons.”

The new policy meant that a transgender butcher charged with abduction following the disappearance of an 11-year-old girl in the Scottish borders was taken to a male jail on Thursday.

Andrew Miller, also known as Amy, appeared at court wearing red nail varnish and entered no plea and was remanded in custody. The girl was found “safe and well” on Monday after being missing for more than a day.

In an announcement on Thursday, the SNP government said: “Newly convicted or remanded transgender prisoners will be placed in an establishment that aligns with their gender at birth.”

This went much further than a new policy announced in the days immediately after the Bryson scandal erupted, when Mr Brown said this would only apply to trans prisoners “with any history of violence against women”. The blanket rules, based on biological sex, only apply to “initial” decisions over where to send prisoners.

The new policy added that ministerial approval would be needed in cases where there were “exceptional circumstances” in which a trans woman with a history of violence against women might be placed in the female estate.

Ms Sturgeon is under significant pressure over her stance on gender issues, which polls suggest is at odds with the views of the Scottish public.

At Holyrood on Thursday, she refused for at least the 13th time to state whether she believes Bryson, who was moved to a male jail after a major backlash, to be a male or female.

The review, carried out by the prison service and its findings accepted by Teresa Medhurst, its chief executive, found that other inmates had not been at risk during the 31-year-old’s time in a female jail.

However, campaigners have said even the presence of a male-bodied prisoner, and particularly a rapist, risks traumatising other women prisoners, many of whom have suffered violence.

Mr Brown said: “It is important that consideration of issues relating to the management of prisoners is measured and does not retraumatise victims or risk unintended consequences for transgender people or individuals in the care of SPS.”