John Humphrys, the so-called rottweiler of Radio 4, is in fact a pussycat. This would have been more of a surprise if I were one of the six million-odd regular listeners of the Today programme, where Humphrys has honed his interrupting skills with filibustering politicians over the past 21 years, but since I can think of nothing less soothing than starting my day with the soundtrack of argumentative discourse on governmental policy, this is not the case.

Journalists tend to be the most unrewarding interviewees and in some respects Humphrys is no exception. He is more careful than the most circumspect politician, super-alert to the possibility that he might be tripped up by a trick question into revealing more than is good for him. I had no idea, for instance, that his job would make him quite so paranoid about discussing politics in any shape or form – which is a bit like interviewing Peter Hall and discovering that he will not comment on the future of theatre.

This means that we cannot talk about the rise of the New Tories other than in the blandest terms: “It’s exactly what happened in 1997, isn’t it? It’s the political wheel turning. It’s what happens. Whether it will continue…” Do you think it will? “Well, I wouldn’t like to offer a judgment about that. I can’t because I’m making a political judgment. I can’t. I really can’t. Do you see? I know it’s silly of me. It isn’t silly of me. No, it’s sensible.” Not for the first time, I have the sense that he is arguing with himself. “I know it’s boring.” It is a bit boring. “I’m sorry, but I can’t honestly say to you, ‘Yes, I think David Cameron is going to smash Gordon Brown at the next election.’” What he will say is: “We’ve had 13 years effectively of New Labour ascendancy – only 11 years in power, admittedly [he includes the last two years of Major’s reign] – but it will be 15 years by the time, if Brown is thrown out at the next election.” Which will be? “My guess is May 2010 but...” Are you good at such predictions? “Hopeless. Almost always get it wrong – hopeless.”

This “I’m hopeless” refrain is another surprise. I’ve never come across a man who puts himself down so frequently in a series of pre-emptive strikes against himself, and I had rather thought, but this was before our meeting, that Humphrys might suffer from a certain smug self-regard.

Referring to a live interview he did with Tracey Emin – who apparently told him that he was the rudest man she had ever met – he said, “I – with brilliant, startling originality – suggested to her that maybe she hadn’t won [the Turner prize] because it was an unmade bed and, you know, with the vast depth and knowledge that I have of art, was this hard?” They met again on Have I Got News for You when Humphrys was presenter – “I wasn’t very good. Well, they didn’t ask me back which proved I wasn’t very good. It was good fun but I was nervous. I was all right but I don’t have that… I don’t have the Boris [magic?]…” Another unfinished sentence. He doesn’t get to see the programme very often, he says, because (with his 3.30am wake-up call for Today) it’s too late for him.

We have a long verbal ramble around the tricky task of interviewing politicians. Why Humphrys continues to be essential listening for many journalists – and the reason why he is so popular with listeners generally – is that he simply will not allow politicians to waffle on without answering his questions. The alternative to not interrupting them would be to allow them to use their alloted slot to get their point across unchallenged. What is interesting is that Humphrys himself is a bit of a waffler.

His conversation is peppered with “Here’s another little digression” and “I’ll answer your question in a minute”. At one point I’m exasperated enough to interrupt The Great Interrupter himself: “Where is this going, John?” And several minutes later (bewildered): “I’m getting a bit… I don’t know where we’re going with this…” “I know. I know,” he says, then, “That’s not my fault, that’s your fault – you’re the interviewer,” which is a fair point, but then my rottweiler skills are clearly no match for his.

The point Humphrys seems to want to get across is that he has been unfairly cast as an aggressive interviewer. When he started out he admits that this was true: “I suppose I thought, ‘I’ve got to make a name for myself and prove that I’m tougher than anybody else.’” He still winces when I mention an interview with John Hume, then leader of SDLP, in 1993, which commentators described as particularly bullying. “It’s hard to bully John Hume because he’s a very tough guy and bright but, yeah, that was bad. I was trying to make a name for myself and I was showing off. The audience has an immense sense of fairness, spotted it instantly and quite rightly ripped me apart.”

He goes on to say: “There is a great myth, I think, about interviewing – and you’d expect me to say this, I know, and it’s a bit self-serving and the rest of it, given the kind of interviewer that I am seen to be – which is that if you were only a bit nicer to politicians and treat them with, give them...They will tell you all kinds of things they didn’t intend to say. That I think is absolute tosh because the kind of people that are likely to be interviewed, the ones in Cabinet or whatever, are very, very bright by and large, and know when they come on exactly what it is they want to say.

“And if you looked at every serious political interview I’d done over the past 21 years, a handful of those would have been pretty devastating for the politician, a handful will have resulted in utter demolition of the interviewer, and most of them will have been neither – which is a very ungrabby answer from your point of view, but it’s honestly the way it is.”

He says that learning about policies is secondary and that his primary mission is to leave the listener with a bit more insight into the character of the politician. There are plenty of political commentators who know far more than he does about what’s going on in Westminster. Humphrys has always maintained an outsider’s distance from those particular corridors but, “even if I do an interview that is information-light – where you don’t learn anything that will make a front-page splash on your newspaper the following morning – if I’ve done my job properly you will still have learnt something because what I try to do is get under the skin of the politician.”

In a chatty telephone conversation we had before meeting up, Humphrys mentioned a smart party he’d once attended with a girlfriend he was trying to impress. The host was David Frost, who welcomed him like a long-lost friend – although they had never met – asking about his two grown-up children by name. This was useful for gaining kudos points with his date, but what intrigued Humphrys was that Frost had been similarly briefed to greet every guest as he worked the room. Part of him was clearly impressed by such conscientious schmoozing but, I suspect, a greater part of him rather despised it. Certainly, he seems to have a bit of a thing about Frost since he has beefed about the man’s interviewing technique many times over the years.

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