In mid-July 2026, Andy Burnham became the UK’s seventh prime minister in a decade after succeeding Keir Starmer. Starmer had announced his resignation as Labour leader and prime minister in late June following poor local election results in May, low personal popularity, economic stagnation, internal party discontent, and controversies including the appointment (and later dismissal) of Peter Mandelson as ambassador to the US. Burnham, the popular former Mayor of Greater Manche

Why the by-election happened Andy Burnham had been Mayor of Greater Manchester since the role was created, winning elections in 2017, 2021 and 2024. In June 2026 he won a parliamentary by-election in Makerfield and returned to the House of Commons. Because the Greater Manchester mayor also holds Police and Crime Commissioner powers, the law disqualifies the post-holder from sitting as an MP at the same time. Burnham’s election as MP therefore automatically ended his mayoralty