Voters in Makerfield go to the polls tomorrow in what has become a cliché to report as the most consequential by-election in modern British history. Either current Mayor of Greater Manchester, Andy Burnham, wins, putting him on the fast track to Downing Street. Or Reform score another by-election win in a north-western former Labour stronghold. Polling in Makerfield points to a Burnham victory, and perhaps even a comfortable one. The betting markets give him around an 80% chance of winning.