Ed Miliband has scored a minor historic first by being the only unmarried man ever to be elected leader of the Labour Party – though that says more about how society has changed than it says about him.
He is in a relationship with Justine Thornton, a 40-year-old, Cambridge-educated environmental lawyer. They have an 15-month-old son, Daniel, and another boy is due in November – raising the possibility that in 40 years the brothers will be fighting to follow their father's footsteps as leader of the Labour Party.
Until the 1990s, the revelation that a politician had had a child outside marriage was potentially career destroying, and one Sunday paper referred yesterday to the old-fashioned concept of "wedlock", but the new Labour leader's married status is unlikely to affect his standing with the public.
When questioned about his status by The Mail on Sunday, Mr Miliband said that he thought they would get around to getting married, but did not say when.
"Ed does believe in marriage," said a spokeswoman yesterday, "but he doesn't think for one second that he loves Justine any less or that they are in any less of a strong relationship because they aren't married."
Ms Thornton was in Manchester to witness her partner's triumph, but headed back to London yesterday. She will return tomorrow to listen to him deliver his first leader's speech. Like Nick Clegg's wife, Miriam, she will continue with her legal career rather than give up her job, like Samantha Cameron, and drop into the role of a politician's wife.
The couple met five years ago, and live together in Primrose Hill, north London, close to where the Miliband brothers grew up. David Miliband lives nearby.
They kept their relationship out of the public eye until March last year, when right-wing newspapers went on the attack because he was the climate change secretary, and she was advising Eon, the German energy company.
The Department of Energy and Climate Change asserted that Ms Thornton had not worked on any cases "in which DECC is the decision-maker".