Andy Burnham holds a clear lead in the Makerfield by-election market because he secured Labour’s nomination following Josh Simons’ resignation on 14 May 2026, positioning the Greater Manchester mayor to return to Westminster and pursue party leadership. Traders price Reform UK’s Robert Kenyon at 31 percent after his strong 2024 showing and recent local election gains across Wigan wards, reflecting Reform’s momentum in northern seats amid national polling shifts. Minor candidates remain sidelined as the contest narrows to these two frontrunners, with no other party mounting a credible challenge before the expected June vote. The current pricing captures the race’s competitive dynamics, where Burnham’s profile and Labour organisation provide the edge while Kenyon’s local appeal keeps Reform within striking distance.