Andy Burnham’s triumph in the Makerfield byelection leaves the prime minister with only two options: fight openly for the Labour leadership, or leave office cleanly. The former Greater Manchester mayor easily saw off Reform UK’s candidate – winning 55% of the vote to his rightwing rival’s 35%. He won largely because he changed the political meaning of voting Labour in Makerfield. With Mr Burnham, the party went from being the unpopular incumbent to being the vehicle for change.

The prime minister’s implicit claim that it was Starmerism that beat Reform is not credible. The polling by Persuasion UK in Makerfield shows that Labour won because of Mr Burnham’s personal brand, anti-Starmer signalling and leftwing economic message. Significantly, Mr Burnham’s victory rally speech on Friday connects with the data. He was offering, in........

© The Guardian