A proposed new law to get more women into the Welsh Parliament may be unlawful, the UK's equality watchdog has said.
The Equality and Human Rights Commission (EHRC) warned that the law could breach the Equality Act if candidates can self-identify as women, even if that is not their legal sex.
Welsh government ministers want political parties to draw up lists of candidates containing at least 50 per cent women for Senedd elections.
The Welsh government said political parties would risk legal challenge if they do not provide accurate information.
The proposals are part of the plans to reform the Senedd with more members.
The EHRC's concerns were raised in a letter to the Welsh Parliament committee looking at the plans.