Sir Keir Starmer has been accused of treating women's rights as 'negotiable' over his failure to enforce the Supreme Court ruling for the past year.

The Prime Minister is also facing demands to explain why his Government believes long-delayed rules on single-sex spaces cannot be published before next month's elections.

He was put on the spot on the first anniversary of the landmark ruling by the campaigners who won the case, For Women Scotland, as they hand-delivered their letter to him in Downing Street.

As the Daily Mail revealed, hundreds of public bodies are continuing to defy the judgment by allowing men who identify as transgender women to use female-only spaces such as toilets and changing rooms.

Many NHS trusts, councils and police forces say they are still waiting to see an updated Code of Practice submitted by the Equality and Human Rights Commission (EHRC) last September.

But ministers claimed this week it cannot be published yet because of 'purdah' rules restricting Government announcements in the weeks before voters go to the polls.

Sir Keir was told in the new letter by Trina Budge, Marion Calder and Susan Smith from For Women Scotland: 'We understand that Purdah rules do not preclude laying a statutory instrument so we remain unconvinced that there is a need to delay until May. We would like an answer regarding the legal basis for this decision.

'It is imperative that you, as our Prime Minister, provide clear and decisive leadership, rather than allowing the status quo to continue to the detriment of women and girls.'

He was warned: 'Failure to do so gives the impression that the rights of women and girls are of lesser importance and negotiable to you. How can your Government have a commitment to halve violence against women and girls, when it refuses to enforce that law which defines what a woman is?'

The Health Secretary insisted that the guidance was 'ready' but cannot be published ahead of elections to the Scottish and Welsh parliaments on May 7th. He had claimed a year ago that it would be issued before summer 2025.

Wes Streeting told LBC radio that transgender people's rights in places such as hospitals also had to be protected as well as those of women.

He asked: 'What do we do about that biological female who is a trans man, looks, sounds, presents, lives his life as a man, is biologically female?

'We wouldn't put him on a women's ward that would be degrading for him, and humiliating and cruel, it would also be distressing for the women. So we need to make sure that we've got trans-inclusive spaces too.'

But Maya Forstater, chief executive of charity Sex Matters, said: 'When not a single NHS trust in the UK is complying with the Equality Act and providing single-sex wards, the Health Secretary's focus on women who identify as male is pure deflection.

'It distracts attention away from the uncomfortable truth that men who identify as women are being greenlighted to enter female-only wards, changing rooms and toilets across the NHS.

'Women whose appearance has been altered through hormones and surgery to look like men, many of whom are young and vulnerable, need to be accommodated too. But that cannot be an excuse for delaying the exclusion of men from women-only wards.'

And Shadow Equalities Minister Claire Coutinho said: 'Wes Streeting promised clear NHS guidance months ago, yet hospitals are still waiting. This delay is a failure of leadership, plain and simple.'