So, Ken Livingstone, do you like Boris personally? ‘No’

I am standing outside Ken Livingstone’s family home in a pleasant row of terraces in the multi-ethnic, north-west London suburb of Willesden Green (commemorated in the novel White Teeth by the novelist Zadie Smith, perhaps the most widely celebrated daughter of the parish).

If the authenticity of a Labour politician’s socialism can be gauged by the size of his house after leaving office, then Livingstone certainly has the edge on Tony Blair: it’s a long way from the hauteur of Blair’s main residence in Connaught Square. I ring the bell, but no one appears to be in.

Then the 69-year-old former London mayor strolls up the street after doing the school run for his two younger children, aged 10 and 11, by his wife Emma Beal. The one-time scourge of New Labour is in good nick: lightly tanned, jeans-clad, and now without that ashen tinge of exhaustion politicians acquire when they spend too long squinting at policy documents late into the night.