Andy Burnham leads the Makerfield by-election market at 79.5% because the 18 June 2026 contest was triggered by Labour MP Josh Simons resigning specifically to give the Greater Manchester mayor a route back into Parliament, enabling a potential leadership challenge against Keir Starmer. Burnham’s local roots in the constituency, strong name recognition, and campaign focus on regional issues have translated into a consistent polling advantage over Reform UK’s Robert Kenyon, a local councillor and plumber whose party shows stronger generic-ballot support but trails in the named-candidate race. Minor candidates including Rebecca Shepherd trail far behind, reflecting limited national profile and the binary dynamic between the two main contenders. Voter surveys highlight widespread dissatisfaction with national Labour performance, yet Burnham’s personal appeal continues to anchor trader consensus ahead of polling day.