The worst thing to happen to Keir Starmer this year has just happened. No, not the tanking economy, nor the foreign policy humiliation, nor the controversy surrounding his anti-corruption minister. It’s not even the disgrace of Labour’s vote against a public inquiry into the grooming gangs.

Rather, it’s that Andy Burnham, the Labour Mayor of Greater Manchester, has said that there should be an inquiry.

This is a big deal. Starmer desperately needs this issue out of the headlines — and his strategy for achieving that depends on complete Labour unity. It’s notable that not one of the 402 MPs currently on the Government benches voted for the inquiry this week. The Conservative amendment was resoundingly defeated, appearing to kill the story. Not for the first time, the implicit message was: shut up and move on.

That’s why Burnham’s intervention is so spectacularly unhelpful. It’s certainly well-timed for the weekend papers. This goes well beyond mere embarrassment for Downing Street. Burnham isn’t just any mayor: he’s Labour’s lost leader, but perhaps not lost forever.

Though he’s seven years younger than the current party leader, Burnham belongs to an earlier generation of Labour politicians, shaped by the Tony Blair and Gordon Brown years. While Starmer was still pursuing his legal career, Burnham served as a minister under Blair and a cabinet minister under Brown — but without being marked by the factional rivalry between the two men. That should have put him in a prime position to succeed Ed Miliband as party leader in 2015, but his ambitions were derailed by Jeremy Corbyn. In a further contrast to Starmer, who chose the path of collaboration with the Corbynites, Burnham opted for exile, leaving Westminster in 2017 for the mayoralty of Greater Manchester.

Burnham is New Labour, not Blue Labour, and to the extent that he has a coherent ideology, there’s not much evidence of post-liberal influence or of his own Catholic upbringing. But the metropolitan bubble is much thinner in Greater Manchester than it is in London, and as the city’s popular mayor he’s clearly more in touch with ordinary voters than Labour’s national leadership. From cancelling winter fuel payments to accepting free gifts of flashy clothing, it’s hard to imagine him making so many of Starmer’s unforced errors.

Burnham will understand the implications of certain council by-elections wins by Reform and what they mean for Labour MPs in Northern England, the Midlands and Wales. Indeed, the latest polls show that scores of seats are now under threat from Nigel Farage’s party. To head off this threat, Labour needs to lean into the populist mood on both cultural and economic issues. In the last week, Burnham has shown how it’s done, siding with 76% of Britons on the grooming gang inquiry while pulling off a public takeover of Manchester’s previously privatised bus services.

Until now, Starmer has been protected by the lack of an obvious successor. No matter how badly he flounders, one looks in vain for a Labour MP who could offer a credible change of direction. But if Burnham returned to Westminster, then the party would have a hard reset button within reach.

How soon might the Manchester mayor make the journey south? His third term isn’t up until 2028, which would be convenient for the next general election. It might even suit Starmer, who will be of retirement age by the end of the decade.

But watch out for an earlier return to Westminster. If the King in the North turns up on Starmer’s doorstep in the next year or two, it might spark a less than peaceful succession.

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