The Labour mayor has splashed £8,000 on online adverts championing niche local concerns ahead of the June 18 vote.

It’s not just the June 18 Makerfield by-election: the anti-immigration party to the right of Reform has its eyes on a nationwide battle.

The candidates in the Makerfield by-election may have been campaigning relentlessly on local issues like flooding, policing and housing, but has there ever been a by-election with…