The prime minister may have seen off the challenge for the moment – but what will be the cost to his leadership? Peter Walker reports

Ever since Andy Burnham abandoned Westminster to become Greater Manchester’s first ever mayor in 2017, he has been dogged with questions about returning to parliament for the top job. He never hid his ambition to become prime minister one day – he couldn’t, really, given that he tried and failed twice to become Labour party leader. But he insisted time and again that he was perfectly happy back in his beloved north, and had no plans to get back to London.

Then on Saturday night, he finally cracked. He wrote to Labour’s ruling body to ask for permission to stand in Gorton and Denton, promising a “hopeful and unifying campaign”, in what he admitted was a risky move. Winning the byelection was not a given and he would have to give up being the mayor if he succeeded. But instead he was blocked by the committee, including Keir Starmer, from standing at all.