Watching anorak-clad Andy Burnham go toe-to-toe with Boris Johnson might leave Westminster-watchers of a certain vintage a bit bemused. How did the Burnham we used to know in the noughties become Manc lad-in-chief, a political brawler who gives brick-chewing interviews on the pavement?

And perhaps more interestingly, what would have happened if the Burnham of earlier decades had shown the fighting spirit of today’s incarnation? British history might have been quite different.