Status: đ´ Former Downing Street Chief of Staff. Architect of the Labour Partyâs anti-trans policy shift, according to Dame Emily Thornberry. Left office February 2026 after the Mandelson-Epstein scandal.
Morgan McSweeney served as Downing Street Chief of Staff under Keir Starmer from October 2024 to February 2026. He was the driving force behind the Labour Together organization that captured the party and shifted it rightward, and Dame Emily Thornberry has publicly blamed him for steering the Labour Party towards an anti-trans position.
According to Dame Emily Thornberry, speaking on the BBCâs Political Thinking podcast (March 2026):
âShe singled out former chief of staff Morgan McSweeney, who left Downing Street last month, for steering the party into territory that âdidnât come naturallyâ to Labour MPs.â
âLabour had stopped âfollowing our heartsâ on trans rights, instead allowing itself to be pushed towards a more socially conservative position by senior advisers.â
Thornberry argued that Labour has a âmoral dutyâ to protect trans people, asking:
âIf the Labour Party doesnât look after trans people, what are we about?â
Scene Magazine: Emily Thornberry interview (March 2026)
McSweeney was the operational architect connecting:
Blue Labour ideology (Glasman, Cruddas)
+ Hedge fund money (Chinn, Taylor)
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Labour Together (run by McSweeney)
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Starmer leadership victory
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McSweeney as Chief of Staff
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Anti-trans policy implementation (Streeting as Health Secretary)
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2026 leadership crisis triggered by Streeting resignation
McSweeney was a key architect of Labourâs electoral strategy, credited with the partyâs âshift to the political centre.â
Before becoming Chief of Staff, he ran Labour Together, an anti-Corbyn organisation co-founded by Maurice Glasman.
McSweeneyâs anti-trans architecture had far-reaching consequences. The policies implemented by Wes Streeting as Health Secretary â including the puberty blocker ban, hormone prescription pause, and threats against GP practices â were built on the political foundation McSweeney created.
When Streeting resigned from Starmerâs cabinet on May 14, 2026, and called for the Prime Minister to step down, it was the culmination of the factional realignment that McSweeney had engineered. Streetingâs leadership challenge exposed the fractures within the Labour Party that had been papered over since McSweeneyâs departure.
The crisis raised questions about whether the anti-trans strategy had backfired electorally, with Labour bleeding support to Reform UK under Nigel Farage.
McSweeney resigned in February 2026 over his role in recommending Peter Mandelson as US Ambassador. Mandelson was subsequently arrested on suspicion of misconduct in public office related to his connections to Jeffrey Epstein.
The McSweeney-Mandelson relationship raises questions about influence networks within Labour:
McSweeneyâs recommendation of Mandelson as Ambassador ultimately led to his own resignation when the Epstein connections became public.