Jim McMahon was elected as Labour and Co-operative MP for Oldham West and Royton in a December 2015 by-election following the death of Michael Meacher. Following the 2024 boundary changes he now represents Oldham West, Chadderton and Royton. He left ministerial office on 6 September 2025, succeeded by Alison McGovern.

Born in Miles Platting, Manchester, in 1980, McMahon has one of the most working-class biographies in current Labour politics. He left school at sixteen, became an apprentice technician at Oldham College, then worked as a regeneration officer and town centre manager in Oldham before entering politics full-time.

His council career was substantial. He was first elected to Oldham Council for Failsworth East ward in a by-election on 20 November 2003, aged twenty-three, succeeding Charles Glover. He became Leader of the Labour Group in 2008 when the Liberal Democrats took control of the authority, led Labour from opposition back to council control in 2011, and served as Leader of Oldham Council from 5 May 2011 to 16 January 2016, succeeding Howard Sykes and being succeeded by Jean Stretton. He was named Council Leader of the Year in February 2014 by the Local Government Information Unit, and was awarded an OBE in 2015 for services to the community in Oldham. He finally resigned his council seat in January 2017, triggering a by-election on 16 February 2017, to focus on his shadow ministerial role.

After entering Parliament, his progression was steady. He served as PPS to Tom Watson while Watson was Deputy Leader of the Labour Party, then was appointed Shadow Minister for Communities and Local Government, with the Devolution brief, in October 2016. The role was expanded to include Local Government and Housing Finance from January 2018. He became Shadow Transport Secretary in April 2020 under Keir Starmer, then Shadow Secretary of State for Environment, Food and Rural Affairs from November 2021 to September 2023.

On 4 September 2023 he resigned from the Shadow Cabinet, citing ill health and, in his own account, threats he had received while serving as Shadow EFRA Secretary. The resignation came immediately before that day's wider Starmer reshuffle. He returned to the frontbench in November 2023 as Shadow Minister for English Devolution and Local Government under Angela Rayner.

Following Labour's 2024 victory, McMahon was briefly appointed Minister of State at the Department for Levelling Up, Housing and Communities on 6 July 2024 as the department was being renamed, before being formally appointed Minister of State for Local Government and English Devolution at the renamed Ministry of Housing, Communities and Local Government on 9 July 2024. He held this role for just over fourteen months before leaving the government on 6 September 2025. He was succeeded by Alison McGovern.

He has served as Chair of the Co-operative Party since 3 October 2020, succeeding Chris Herries, an internal party position of real weight given that Labour Co-op MPs now form a substantial bloc of the parliamentary party. He is also a Vice President of the Local Government Association. He supported Keir Starmer in the 2020 Labour leadership election.

His 2024 election majority in the new Oldham West, Chadderton and Royton constituency was 4,976, a 12.9 percent margin, substantially smaller than previous Labour majorities in his old seat. Oldham has become genuinely competitive, given local tensions over community cohesion, the legacy of the historical child sexual exploitation cases that have dominated national political debate again in 2024 and 2025, and broader concerns about local government performance in the borough he led for almost five years.

McMahon's strengths include a genuine working-class background unusual in current Labour politics, sustained council leadership experience including taking Oldham back from the Liberal Democrats, OBE-level recognised public service, substantial shadow cabinet experience across multiple portfolios, the chairmanship of the Co-operative Party, and direct ministerial experience on devolution policy. His weaknesses include departure from ministerial office in September 2025 raising questions about his current trajectory, the September 2023 Shadow Cabinet resignation citing ill health and threats, a narrower electoral majority in the new constituency, and the broader challenge that policy specialisation on devolution rarely translates into broad national profile.

Whether his career continues to develop or has now plateaued depends on whether his September 2025 departure from government was strategic or a setback.