It is six in the evening at the end of a wet and blustery day in Darlington. In the fading light, a pair of black Volkswagen Golfs weave their way through the narrow streets just outside the town centre and come to a halt on an anonymous Victorian terrace.

Welcome to Craig Street, home to a microcosm of British life and for the next hour or so the focus of Labour's battle to win a third term in power. There are no camera crews, no helicopters and no press conferences. Just drizzle, the sound of a dog barking and Alan Milburn, Labour's election campaign co-ordinator and chief architect of its manifesto.