Andy Burnham has championed causes beyond Manchester and now he wants to change the UK (Image: Getty Images) Andy Burnham has just made one of the biggest decisions of his life and it could have huge implications not just for the future of the Labour party but for Britain itself. When a Labour insider in Westminster he twice ran for the leadership but never amassed a following of devotees. Nobody talked about Burnhamism. But when he became Mayor of Greater Manchester he hit his stride, leading the city through the pandemic and becoming one of the greatest advocates of English devolution. He could drop into think tank sessions and talk with pride and enthusiasm for initiatives he had pushed forward, while also earning a reputation as an unpretentious family man rather than a political apparatchik. He has cast himself as both a fount of ideas and as a conscience of the Labour movement. There is no doubt this is a very comfortable perch but he has resolved to jump into the unknown – and he could …