Deirdre Costigan

MP for Ealing Southall

Labour

Deirdre Costigan is the Labour Party MP for Ealing Southall, having first been elected to parliament at the 2024 general election.

In the 2024 general election, Costigan won 23,000 votes, representing 49.1% of the vote. The Conservative candidate, Georgie Calle, received 7,207 votes (15.4%). The Green Party candidate, Neil Reynolds, secured 4,356 votes (9.3%). Costigan was duly elected with a majority of 15,793.

The Ealing Southall constituency is located in the London Borough of Ealing, West London. It has been held by the Labour Party since its creation in 1983.

Costigan’s immediate predecessor as the for MP Ealing Southall was Virendra Sharma of the Labour Party. Sharma, who represented the seat from 2007 to 2024, stood down at the 2024 election.

Political Career

Costigan currently serves as a parliamentary private secretary (PPS) in the Department for Business, Innovation, Science and Trade. A PPS acts as an unpaid parliamentary assistant, providing a link between the senior frontbencher and backbench MPs. The role is widely regarded as the first step on the ministerial ladder. Although they cannot speak for the government in debates, a PPS is bound by collective responsibility and becomes part of the so-called “payroll vote”, expected to support the official line in all divisions. Costigan was appointed to this role in July 2026, following the Labour leadership contest and Andy Burnham’s elevation as prime minister.

Costigan served as a junior lord of the Treasury (government whip) from May to July 2026. Her appointment to this post was part of a targeted reshuffle designed to stabilise Keir Starmer’s position as prime minister after a series of resignations.

Costigan served as an assistant government whip from September 2025 to May 2026.

Costigan has also served as a PPS in the Department for Health and Social Care (2025).

In May 2025, Costigan introduced a private members’ bill (PMB) under the 10-minute rule procedure to mandate deadlines for employer responses to reasonable adjustment requests from disabled workers. She told the House that during her time as a union representative, she found that it was “disabled workers more than any others who were facing problems.”

The Reasonable Adjustments (Duty on Employers to Respond) Bill called for a “clear deadline” for employers to reply to disabled workers making a request for reasonable adjustments.

Costigan stated: “My bill would give a right to a response to reasonable adjustment requests to the five million disabled people already in work, and it would help open up jobs to hundreds and thousands of disabled people who want to work, but I look forward to seeing what other ideas the report identifies.”

Costigan sat as a member of the House of Commons health and social care committee from October 2024 and March 2025.

Costigan is a patron of LGBT+ Labour – a socialist society formally affiliated with the Labour Party.

Costigan delivered her maiden speech in the House of Commons on 18 July 2024 in a debate on foreign affairs and defence.

In it, she said: “I came to this country in the 1990s to finish my education, but like so many Irish people before me, I fell in love with the diversity of this country, and I never went back. That is the story of my constituency, Ealing Southall, where 53% of people were, like me, born abroad.

“Whether from India, Pakistan, Somalia, Sri Lanka, Afghanistan, Ireland or so many other places, we all came here for a better life, but we did not always find it easy to achieve that better life. Many of my constituents have faced barriers in the workplace and on the streets, but they have always stood up to them.”

She added: “When I had my stroke, the care that I received from an Irish neurologist working for NHS North West London was fantastic, so I applaud the investment that Labour is making in reducing NHS waiting lists and doubling scanners for quicker diagnoses.

“I am not sure that I would be here today if it was not for our NHS. We must again ensure that it is the best health service in the world.”

Before entering parliament, Costigan was elected to serve as a Labour councillor on Ealing London Borough Council in 2018. She resigned from this post following her election as an MP, having served as the council’s deputy leader from 2021 to 2024.

Political views

Factional identity and party tradition

Trade Union Group: Costigan is vice-chair of the Trade Union Group of Labour MPs executive. This long-standing group, founded in 1926, serves as a link between the Labour party and the trade union movement, aiming to ensure that the voices of working people and their unions are represented in parliament.

SERA: Costigan has been listed as a member of the Socialist Environment and Resources Association (SERA) – a socialist society affiliated with the Labour Party. Founded in 1973, SERA is the party’s official environmental campaign group. The organisation campaigns on a wide range of issues, including renewable energy, biodiversity, air quality and the transition to a green economy. SERA describes its member MPs as “champions for the environment”.

Welfare

Welfare vote (July 2025): Costigan voted in favour of the government’s flagship welfare bill at second reading. The vote came after ministers agreed to significant concessions to avoid defeat via a mass rebellion of Labour MPs on 1 July 2025.

Assisted dying

Costigan voted in favour of the Terminally Ill Adults (End of Life) Bill, better known as the assisted dying bill, at both second reading (November 2024) and third reading (June 2025).

Social values and conscience issues

Abortion decriminalisation (2025): Costigan voted in favour of a backbench amendment to the Crime and Policing Bill that sought to decriminalise abortion in England and Wales in June 2025. The amendment, which was passed by a majority of 242 votes, removed women from the threat of prosecution for ending a pregnancy at any stage. As an issue of conscience, MPs were allowed to vote according to their personal beliefs.