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