Labour’s former health minister Andrew Gwynne has confirmed he is stepping down as an MP, triggering a by-election in Gorton and Denton that has immediately reignited speculation Andy Burnham could seek a route back to Westminster — but a new Labour rule means the Greater Manchester mayor can be blocked before the selection process even begins.
Gwynne, who has represented the area in Parliament since 2005 and won the newly drawn Gorton and Denton seat at the 2024 general election, said he was resigning on medical advice after a prolonged period of ill health. The by-election date has not yet been announced.
The vacancy has been widely discussed in Labour circles as a potential opening for Burnham, one of the party’s best-known regional figures and a former leadership contender, to return to the Commons. However, party rules introduced in Labour’s 2026 rule book create a significant procedural hurdle for directly elected mayors seeking to become MPs.
The rule states: “Directly Elected Mayors and Police and Crime Commissioners must seek the express permission of the NEC/SEC/WEC (as applicable) before seeking nomination as Labour candidates for the Westminster Parliament. The NEC/SEC/WEC’s decision shall be final.”
That change means Burnham would need the backing of Labour’s National Executive Committee to stand, rather than being able to rely solely on local party support. It also means Labour’s national structures can refuse permission outright, without Burnham ever reaching the constituency selection stage.
Burnham would also be expected to stand down as mayor to contest a Westminster seat, triggering a separate mayoral election in Greater Manchester. Labour is not guaranteed to retain the mayoralty if it becomes vacant, and the contest would also carry a significant public cost, reported to be in the hundreds of thousands of pounds.
Senior figures close to Sir Keir Starmer have been described as determined to prevent Burnham returning to Parliament, amid wider talk that an MP seat could position the mayor as a future contender for the Labour leadership.
Sky News political correspondent Sam Coates reported he had been told Starmer’s chief of staff, Morgan McSweeney, believes he has sufficient support on the NEC to block Burnham if necessary.
The Prime Minister sought to shut down the leadership speculation, telling Channel 4 News: “My message is to my entire party, and that is: that every minute we waste talking about anything other than the cost of living and stability in Europe and across the globe is a wasted minute.”
Burnham has not said he intends to stand, and urged caution over assumptions about his next steps. “People shouldn’t rush to conclusions,” he said. “I have been very focused on my role as Mayor of Greater Manchester.”
If Burnham were granted the NEC’s permission to seek nomination, he would still face a further process controlled by the party’s selection machinery. Under Labour procedures, the NEC is involved in producing a longlist and a shortlist of candidates. The longlist is typically handled by email among NEC members, while the shortlist is drawn up by a panel.
That panel comprises three NEC members, one party board member and a local constituency representative. The panel is appointed through the office of Labour’s general secretary, Hollie Ridley, who is viewed by some in the party as close to the current leadership team.
One NEC member, Cat Arnold, warned against narrowing the choice of candidates. “There must be a free and fair selection, at long list and shortlist stage,” she told Sky News. “It would be completely unacceptable to gerrymander or unduly narrow the list of potential candidates.”
Gorton and Denton has been a reliably Labour seat, with Labour winning in 2024 on 50.8% of the vote and a majority of 13,413. Gwynne was later suspended from the party after offensive WhatsApp messages emerged, having been sacked as a minister in February 2025, and subsequently sat as an independent.
Opponents have also moved quickly to frame the by-election as a test of Labour’s grip on the seat and its internal unity. Conservative politician Robert Jenrick said: “We will be fielding a strong candidate, and if you want to send a message to Keir Starmer in that election, then I’d urge local people to vote Reform.” The Green Party said it intended to contest the seat strongly, declaring: “We were deadly serious when we said we are not here to be disappointed with Labour, but we are here to replace them.”
While any leadership challenge would depend on parliamentary arithmetic and party rules — including the need for substantial MP nominations — the immediate question is whether Burnham is permitted by Labour’s governing body to seek selection at all.
For now, Labour has not confirmed the timetable for the by-election, nor indicated whether the NEC has been approached for permission in relation to any prospective candidate. The coming days are expected to bring further pressure from across the party as it decides whether one of its highest-profile mayors will be allowed to contest a route back to Parliament.