The Conservatives have promised to rewrite the Equality Act so that protections it enshrines on the basis of a person’s sex apply only to their biological sex.

Prime Minister Rishi Sunak said the “safety of women and girls” meant the “current confusion around definitions of sex and gender” cannot be allowed to continue.

The Tories say their election pledge will make it simpler for service providers for women and girls, such as those running sessions for domestic abuse victims, to stop biological males from taking part.

Labour, the Liberal Democrats and Scottish National Party (SNP) have not yet commented on the proposals.

Under the Equality Act 2010, it illegal to discriminate against anyone because of “protected characteristics”.

These are a set of identifying traits that are protected by law and include age, disability, religion, race, sex and sexual orientation among others.

Some interpret sex in this context as referring strictly to biological sex, while others believe it also applies to people with a gender recognition certificate; a legal document that allows someone to change the legal sex on their birth certificate.

The Conservatives want to change the Act to apply to biological sex, and say single-sex spaces and services must not be open to those who are biologically male but identify as female.

The party says that since the Equality Act was introduced in 2010, it has not kept up with “evolving interpretations” of sex and gender.

The Conservatives are presenting their pledge as a matter of privacy and principle.

But it is also an issue that may appeal to socially conservative voters who previously voted for the party but, polls suggest, might not vote for them this time.

Tory strategists hope it will also put other parties on the spot about where they stand on the issue.

Critics have, in the past, accused the Conservatives of seeking to stoke divisions and demonise transgender people in the search for votes.

Under the plans, existing protections for transgender people would remain.

Mr Sunak said: “The safety of women and girls is too important to allow the current confusion around definitions of sex and gender to persist.

“The Conservatives believe that making this change in law will enhance protections in a way that respects the privacy and dignity of everyone in society.”

Writing in the Times, the minister for women and equalities, Kemi Badenoch, said “clarification” was needed as “it is clear public authorities and regulatory bodies are confused about what the law says and what to do”.

She claimed the changes would provide new protections for biological women in places such as hospital wards and rape crisis centres, or “instances of men playing in women’s sports”.

Ms Badenoch also took aim at Labour leader Sir Keir Starmer for “going round in circles on the issue”.

The Conservatives have also committed to making gender reassignment a reserved issue; meaning it would be uniform policy across the UK nations.

This comes after the UK government last year intervened to stop Scotland enacting its Gender Recognition Reform Bill.

Ms Badenoch said in the Times: “We are one United Kingdom and it is impracticable for gender recognition regimes to vary in different parts of the country. So, we will also legislate to establish that gender recognition is a reserved matter.”

The Equality Act 2010 already allows service providers to exclude certain groups if doing so is considered a “proportionate means” of achieving a “legitimate aim”.

In 2022, the UK’s equality watchdog, The Equality and Human Rights Commission (EHRC), published guidance for service providers wishing to keep spaces – such as bathrooms – single-sex, including examples of when they can legally exclude certain groups in order to do so.

One such example was around access to domestic abuse refuges, with the EHRC advising it would be legal to bar trans women from the refuge, if female survivors indicated they felt uncomfortable.

However, the Conservatives say the existing law is not “sufficiently clear” on when it means biological sex and when it means gender.

In 2022, Judge Lady Haldane concluded the definition of sex in the act was “not limited to biological or birth sex” after a group of campaigners launched a legal case around gender balance on public boards in Scotland.

The Conservatives argue the “ambiguity” of the law means single-sex service providers are often “vulnerable” to legal challenges, and that women and girls’ safety is at risk.

The proposed law change would apply whether or not the person has a gender recognition certificate.

It’s not the first time the Conservatives have spoken about amending the Equality Act.

In 2023, Ms Badenoch wrote to the EHRC for advice on the impact of doing so.

The EHRC’s chair Baroness Kishwer Falkner said it would give clarity in a “polarised and contentious” area, but also warned a change could be “more ambiguous” than the current definition of sex in relation to equal pay and sex discrimination.

She said any changes to the law would need detailed analysis of possible disadvantages for trans men and women in these areas.