Morgan McSweeney

Morgan James McSweeney (born 19 April 1977) is an Irish former political strategist for the British Labour Party. He served as Downing Street Chief of Staff under Prime Minister Keir Starmer from October 2024 until his resignation in February 2026. A close colleague and adviser to Starmer over many years, he was ranked first in a 2024 New Statesman poll on influential people in UK left-wing politics, and has been compared to Dominic Cummings and Peter Mandelson.

McSweeney joined the Labour Party in 1997, motivated by backing for the Good Friday Agreement, and in 2001 he was hired to work as an intern receptionist and then in the party's attack and rebuttal unit in Millbank. From 2008 until 2010, he campaigned with David Evans, Jon Cruddas, Margaret Hodge and Hope not Hate against the British National Party. His father, Tim McSweeney, was a senior partner in an accounting firm. His mother, Carmel McSweeney, was a retired office worker and keen bridge player. His parents supported Fine Gael. His grandfather on his father's side, Michael McSweeney, fought for the Irish Republican Army during the Irish War of Independence and received a medal for it. He supported the pro-treaty side in the Irish Civil War and later joined Fine Gael. Aged 21 in 1998, he went back to university. He studied marketing and politics at Middlesex University and graduated with a degree.

Political career Local Labour organiser In 1997, motivated by backing for the Good Friday Agreement, McSweeney joined the Labour Party, and in 2001 he was hired to work as an intern receptionist and then in the party's attack and rebuttal unit in Millbank, where he input data into Peter Mandelson's "Excalibur" database. also focusing on patriotism and crime as campaign points. Under his leadership, Labour Together worked on a strategy to remove Jeremy Corbyn from the party leadership and to institute reforms to Labour Party processes to prevent the left wing of the party from subsequently regaining the leadership.

In February 2026, it was reported that Labour Together paid the PR firm APCO Worldwide to spy on journalists critical of Starmer. These included reporters from The Sunday Times, The Guardian and Declassified UK. This had also previously been detailed in Paul Holden's book The Fraud. As part of Labour Together's strategy to diminish the influence of the left, he had also worked to prevent the newly founded left-wing news website The Canary from growing in popularity among Labour members, while building a close link between the mainstream centre-left newspaper The Guardian and Labour Together.

Director of campaigns In September 2021 McSweeney was appointed Labour's director of campaigns. The Times has noted that "Those who question his authority inevitably find Starmer sides with McSweeney."

McSweeney led preparations for the 2024 general election, McSweeney made contact with members of the US Democratic Party and Australian Labor Party, respectively Neera Tanden and Anthony Albanese, to discuss election tactics. He argued in a December 2023 shadow cabinet meeting that despite Labour's significant lead in national polls, six different elections from around the world were examples of leads reversing once campaigns began.

Head of political strategy Following Labour's victory in the 2024 general election on 4 July, McSweeney was appointed the head of political strategy alongside Paul Ovenden.

Some media reports suggested in August that McSweeney had come into some tension with Starmer's chief of staff Sue Gray, with McSweeney being more politics-focused and Gray being governance-focused, both allegedly developing rival power centres within 10 Downing Street. McSweeney privately rejected the idea and insisted that he worked well with Gray.

Downing Street chief of staff Following the resignation of Sue Gray, McSweeney was appointed Downing Street Chief of Staff on 6 October 2024. Vidhya Alakeson and Jill Cuthbertson were appointed as his deputies.

In November 2025, Starmer sought to stop briefings by his allies that No 10 feared Wes Streeting could launch a leadership coup. Starmer gathered staff to stress that briefings against cabinet ministers were "unacceptable" after apologising to Streeting. His spokesperson said that Starmer also accepted assurances that No 10 staff had not briefed against Streeting and that he stood by his chief of staff. Previously, McSweeney was accused of briefing against Gray.

Mandelson-Epstein friendship scandal and resignation

In September 2025, when Peter Mandelson was dismissed as ambassador to the United States after further revelations of his close friendship with child sex offender Jeffrey Epstein, it was reported that McSweeney, who was known to be personally close to Mandelson, had been a "keen advocate" for Mandelson's appointment as ambassador despite his involvement with Epstein already being known, and despite concerns raised by the security services during the vetting process. Some Labour MPs were reportedly angry at McSweeney's influence, accusing him of promoting a factional, clique-driven style of politics, especially as allies of Starmer and McSweeney had recently been promoted during a cabinet reshuffle in September 2025.

In October 2025, McSweeney, who was then the Downing Street Chief of Staff, reported his government-issued phone stolen by a cyclist in Westminster. The incident gained significant attention in March 2026 following a parliamentary order for the government to release communications between McSweeney and Mandelson regarding the latter’s appointment as US ambassador. Critics, including Conservative opposition leader Kemi Badenoch, raised concerns about the timing of the theft, while Prime Minister Keir Starmer dismissed suggestions of a "cover-up" as "far-fetched". To provide transparency, the Metropolitan Police released a transcript of McSweeney’s 999 call, which revealed he initially provided an incorrect street name, leading to the case being recorded in the wrong location and subsequently closed. The Met has since reopened the investigation to reassess evidence in the correct area. In February 2026, Starmer defended McSweeney, saying he was an essential part of his team.

On 8 February 2026, following increasing pressure, McSweeney resigned as Starmer's chief of staff. In a written statement, McSweeney took responsibility for the decision to appoint Mandelson, acknowledging it was wrong and had damaged the party and trust in politics. He stated that stepping aside was "the only honourable course". McSweeney expressed pride in the government's achievements, stating that his motivation was always to support a Labour government focused on ordinary people. He also highlighted the importance of remembering the victims of Epstein. Although he did not oversee vetting, he called for it to be fundamentally overhauled. He concluded by affirming his support for Starmer's mission. Starmer accepted McSweeney’s resignation and issued a statement expressing gratitude for his service. Starmer stated that he and the Labour Party owe McSweeney a "debt of gratitude" for his years of service. He credited McSweeney with a central role in the party's electoral success, including the 2024 landslide majority. Starmer praised McSweeney's "dedication, loyalty and leadership" and said it had been an honour to work with him.

Following McSweeney's resignation, The Guardian described the move as a significant political shake-up, highlighting increased scrutiny of Downing Street's vetting procedures. Tim Allan resigned as Director of Communications the following day. Vidhya Alakeson and Jill Cuthbertson were appointed by Starmer as McSweeney's acting successors.

On 22 June 2026, following a a leadership crisis, Starmer resigned as Labour leader and prime minister.

After government

In April 2026, McSweeney was called to give evidence to the Foreign Affairs Select Committee on his role in Mandelson's security vetting. This followed former senior Foreign Office civil servant Olly Robbins alleging that the Prime Minister's office had a "dismissive" attitude towards the vetting process. McSweeney gave a statement to the committee apologising to the victims of Epstein, and was probed by the members of the committee into his role in the appointment of Mandelson as US Ambassador. When referring to revelations including pictures of Mandelson and Epstein that appeared following the former's appointment as ambassador, McSweeney stated it felt like a "knife to my soul". He denied that Mandelson was appointed because he was a "hero" or "mentor", and instead said his motives had been in the national interest throughout the process.

McSweeney attended the Kyiv Security Conference in April 2026. The Sunday Times stated that he was interested in how artificial intelligence might shape future elections in Ukraine.

In July 2026 McSweeney said that Labour had failed to properly prepare for government, and that he had failed around the appointment of Mandelson. He said he expected his next job would be outside politics.

Reputation McSweeney acquired a reputation as a successful Labour organiser, leading campaigns to win a majority on the Lambeth London Borough Council and to defeat the far-right British National Party in Barking and Dagenham though his role and effectivness in relationship to this campaign and labour victory has been questioned. In September 2023, the New Statesman ranked McSweeney third on a list of the most influential left-wing figures in the UK and described him as Starmer's "most trusted aide".

In February 2025, Bethany Dawson of Politico Europe stated that McSweeney "is seen as a key protagonist in the rise of Prime Minister Keir Starmer." James Ball of The New European described McSweeney in May 2025 as "a core foot soldier in the internal resistance to Corbyn during his leadership, and was behind efforts to stamp out dissent once Starmer won," saying that he "has risen to an astonishing level of power and influence with the government, not least through the brutally effective removal of internal rivals." In October 2023, The Times stated that "nobody without elected office wields as much power in British politics as McSweeney",

Jason Cowley of the New Statesman compared McSweeney to Conservative Party adviser Dominic Cummings, saying that both "continue to exert a special fascination," among observers of British politics.

Political positions and ideology Jason Cowley of New Statesman has described McSweeney as a "conservative social democrat." Gabriel Pogrund and Hugh O’Connell of The Sunday Times have described his politics as similar to "the old Labour right: a combination of patriotism, social conservatism, and traditional left economics."

According to George Eaton of New Statesman, McSweeney's political positions were marked by his activism in Lambeth, with McSweeney blaming "far-left sectarianism for enabling the abuse of hundreds of children in the borough’s care homes during the 1980s". According to Robert Shrimsley of The Financial Times, McSweeney believed that the leaderships of Ed Miliband and Jeremy Corbyn "saw Labour divorced from its key voters," and that McSweeney's "contempt for those who prioritised liberal ideals over the ordinary concerns of traditional and patriotic voters convinced him that Labour had to be saved from the left and that Corbynism had to be destroyed." Former Conservative Party minister Michael Gove wrote that McSweeney "believes Labour should fight for working people against the establishment, rather than seek comfortable accommodation with its institutions," and "wanted, above all, the Corbynites to lose, for the role they had played in damaging the Labour party."

Personal life McSweeney is married to Imogen Walker, a Labour politician who has served as the MP for Hamilton and Clyde Valley since 2024, and from September 2025 an assistant government whip. They have a son. McSweeney lives in Lanark, South Lanarkshire.