Keir Starmer is facing one of the most awkward political tests of his leadership as he prepares to campaign for Andy Burnham in the Makerfield by-election, despite growing speculation that the Greater Manchester Mayor could soon become his most serious rival.
On paper, Labour should be united behind Burnham’s expected bid to return to Westminster. Makerfield is a Labour seat, and the party will want to present the campaign as a show of strength in one of its traditional heartlands. But behind the scenes, the contest is being watched for a much bigger reason: it could give Burnham the parliamentary route he needs to launch a future leadership challenge.
That possibility has turned what might otherwise be a routine by-election into a high-stakes drama for Downing Street. Starmer has said he will support Labour’s candidate, but critics inside and outside the party argue that the situation exposes the uncomfortable reality of his position. He may have to publicly campaign for a man many in Westminster believe could one day try to replace him.
The political optics are difficult. If Starmer appears reluctant, he risks looking petty or fearful. If he campaigns enthusiastically, he could help boost the profile of the very figure who may soon become a threat to his authority. Either way, the Makerfield race is no longer just about one constituency. It has become a test of Starmer’s grip on Labour.
Burnham’s supporters see him as a politician with a strong northern identity, a direct communication style and a record of building a personal brand outside Westminster. As Mayor of Greater Manchester, he has often presented himself as someone more connected to local communities than the national political class. That image could prove powerful at a time when many voters feel frustrated with mainstream politics.
For Starmer’s allies, however, Burnham’s possible return creates obvious tension. Labour is already facing pressure over the economy, public services, immigration, welfare and voter trust. A by-election that becomes dominated by leadership speculation could distract from the Government’s agenda and feed the impression that Labour is turning inward.
Some ministers and MPs are reportedly concerned that Burnham’s arrival in Parliament could quickly change the mood inside the party. Even if he does not immediately move against Starmer, his presence would create a permanent alternative around whom unhappy MPs could gather. That alone could weaken the Prime Minister’s authority.
Burnham’s allies, meanwhile, are expected to be careful about timing. A sudden leadership move could be seen as self-serving, especially if he has only just returned to Parliament. There is also the question of Greater Manchester, where his departure as mayor would create another political contest Labour would need to manage.
Still, the speculation is unlikely to disappear. If Burnham wins Makerfield comfortably, he will return to Westminster with momentum. If the result is closer than expected, it could raise fresh questions about Labour’s support in its own heartlands. Either outcome carries risk for Starmer.
The by-election also gives Reform UK and other opposition forces a chance to exploit Labour’s internal tensions. Nigel Farage’s party will be eager to present itself as the real challenger in working-class areas, while Conservatives will likely argue that Labour is already consumed by its own succession drama.
For voters in Makerfield, the campaign may focus on local concerns such as jobs, housing, transport, the NHS and living costs. But for Westminster, the race has become a proxy battle over Labour’s future.
Starmer may insist the party is united. Burnham may insist he is focused on serving the people of Makerfield. But the wider political message is hard to ignore: Labour’s most awkward contest may be the one where the Prime Minister is forced to campaign for the man who could one day challenge him.
