Deirdre Costigan

Deirdre Theresa Costigan is an Irish politician and trade unionist in the UK, who has been the Labour Party Member of Parliament (MP) for Ealing Southall in the United Kingdom House of Commons since 2024.

Early career Costigan was born in Dublin, Ireland, and emigrated to London in the 1990s. She was a shop steward for the trade union Unison. Before her election as an MP, she was Unison's national officer for disability equality. She served as deputy leader of the council for the three years preceding her election in 2024 as an MP.

In the 2024 general election, Costigan was elected the Member of parliament (MP) for Ealing Southall with 23,000 votes (49.1%) and a majority of 15,793 over the second place Conservative candidate. On 18 July 2024, she made her maiden speech during a debate on foreign affairs and defence.

In the September 2025 cabinet reshuffle, Costigan was appointed to the ministerial position of assistant government whip. On 12 May 2026, she was appointed junior lord of the treasury (government whip) following mass resignations from the government.

Personal life Costigan is a lesbian.