The equalities watchdog has called for Labour to justify the decision to bar straight white men from attending an event and warned the move could be “unlawful discrimination”.

Young Labour’s Equalities Conference is billed as a one-day gathering for disabled, LGBT, women and black, Asian and minority ethnic (BAME) members.

White heterosexual men are not listed as eligible to apply to attend the event, which will take place on March 17 in central London.

Conservative MP Andrew Bridgen reported the organisation to the Equality and Human Rights Commission (EHRC).

The watchdog said: “Barring members from participating in events or internal committee elections based on their self-defined race, sexuality, gender or disability, is unlawful discrimination unless it can be shown to be a proportionate way of addressing disadvantage or low levels of participation within party structures.

“We have written to Young Labour to ask them for their justification for these member restrictions.”

The positions of women’s, BAME, disabled, and LGBT+ representative will be elected at the Young Labour conference.

Heterosexual white men are not eligible to vote in the elections, as rules state only women can vote for the women’s representative and only LGBT members can vote for the LGBT officer.

The election of equalities representatives cannot take place online as Labour does not have the relevant data on members’ identities.

Most other positions on the National Committee are voted for using an online ballot.