Author: Peter Walker, Josh Halliday, Jessica Elgot and Kiran Stacey

Keir Starmer is facing an ultimatum from his own party to change direction or risk a leadership challenge within months after the Greens humiliated Labour with a historic byelection victory in Gorton and Denton.Overturning a 13,000 Labour majority from the general election, Hannah Spencer, a local plumber and Green councillor, became the party’s fifth MP on Friday. Reform UK’s Matt Goodwin was second, just ahead of the Labour candidate, Angeliki Stogia.The scale of defeat in an area that had returned Labour MPs for nearly a century, and where Starmer’s party still believed it could win even on polling day, plunged…