Friends have suggested that I am the least qualified person to talk about happiness, because I am often down, and sometimes profoundly depressed. But I think that's where my qualification comes from. Because to know happiness, it helps to know unhappiness.

My dad, Donald, was a vet and had a practice in Yorkshire. Cats and dogs were his bread and butter, but his greatest love was large animals.

Like most meaningful activities, campaigns are team games.

The thing about politicians in Britain is that they are out there, you can lobby them, get close to them, there are loads of ways you can protest against them, and booing is a pretty weak way of doing it.

Paul Keating told us before we were elected that you can do deals with [Rupert] Murdoch without saying you were doing a deal. Did we do that kind of thing? Maybe. But from around about the turn of the century, I felt strongly that we had to do something about media ownership and self-regulation. Tony [Blair] disagreed.

I remember talking to Alex Ferguson about Tony [Blair] and Gordon [Brown], and he said: "Why doesn't Tony just get rid of him?" But if you sack someone in football, they can't turn up to training the next day. In politics they're still on the pitch. Gordon would still have been a big player.

I want to write more books, see my first novel made into a film, fight more campaigns, work in more countries. I want to be able to recall experiences that have endured for their pleasure and range and intensity.