Sir Terry Wogan was 'The Godfather' of broadcasting

"Do you want the full Marion Brando bit?" he asks, giving us a lifelike rendition of the Hollywood legend’s cotton-wool-assisted dialogue, plus a tweak of his cuff links.

"Now where was I? Ah yes, laziness. Seriously, my doing well for myself never ceased to amaze my old dad, who loved me and was proud of my success, but who knew all too well my aversion to anything requiring more than minimal effort.

"The thing is, my old dad was a meticulous, painstaking worker. He started out as manager of a grocery store, then manager of a chain of grocery stores, and then managing director of a chain of grocery stores. I think he would have liked me to become a doctor; as for myself, I rather fancied becoming a journalist, except the training seemed a bit like hard work, so I took the easy option and joined a bank."

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After four years, he answered an ad for an announcer on Irish radio, then joined the BBC in the fledgling days of Radio 1 and 2. "When I started to do well for myself in broadcasting in England, my dad and my mum used to come over, and he’d walk all round our house, shaking his head and giving off these Irish sighs that just went ‘Son!'"

Press the Togfather further (Tog stands for Terry’s Old Geezers or Gals, ie fans of his Radio 2 show) and he insists that his success is built on no more than "doing what is required of me". As for his ability to achieve an instant rapport with any audience, he dismisses it as no more than a "slight gift", backed up by a lifetime’s reluctance either to rehearse or prepare beforehand.

But he reveals he probably wouldn’t have achieved that success if he was just starting out now. "When I sent in my first tape to the Head of Gramophone Programmes at the BBC, I had made the fatal mistake of forgetting to rewind it to the start. Yet that gentleman took the time to wind it all the way back, and once he’d listened to it, things went from there. I can tell you, if I was a young chap coming over from Ireland today, they probably wouldn’t even listen to my tape, let alone rewind it. Somehow, that old-fashioned thoroughness and commitment have disappeared; I suppose no-one has the time for it any more.

"When I started, people who worked for the BBC knew they weren’t earning as much as people in commercial television, but they did have the satisfaction of knowing that they worked for one of the finest, if not the finest, broadcasting organisation in the whole world. I’m not sure they feel that any more, or at least that it means as much as it used to."

Despite his charmed career, Wogan does have one big regret - having done one series too many of his TV chat show, which ran off and on from 1983 to 1992. "I blame myself for not getting off the beach before the tide went out," he says. "Mostly my timing’s been good and I hope that I will know - or at least my family will tell me - when the time comes for me to retire. You certainly know when it’s time for other people to go - you look at them and think, ‘You’re just a beat late’."

But that experience hasn’t stopped him taking on another TV challenge, with a Channel 4 teatime quiz show called Wogan’s Perfect Recall, which begins next week.

"I may be 70, but I think I’m 15, and therefore see no reason not to try new things," he beams. As to whether he will have the same kind of success as Noel Edmonds with Deal or No Deal, he says he doesn’t have a clue. "There are two reasons for doing this show," he says. "One is to see if the public like it, and I think they will as it’s a British idea - so many of these things are formats that come over from America and Australia. The other reason is to see if I’m physically up to recording three shows a day. We’re doing 20 shows in two weeks, so by the end, I should know!"

Cash is clearly not his incentive. "No amount of money - and I mean no amount of money - would be enough to get me out of bed at 5.20am every morning if I wasn’t doing something I loved, ie my radio show. As for the amount of money I am offered to do corporate stuff - a talk, an after-dinner speech - I am astounded by the sums people are prepared to put up. But I rarely accept those engagements, or if I do, I quickly change my mind. It’s the expectant faces I can’t stand, you see, all looking up at me. The thing is, I’m not a comedian; I’m not someone who can stand up on a stage and make people howl with laughter, like Peter Kay or Ronnie Corbett. You have to know your limitations in this business."

One show he almost certainly won’t be doing, though, is next year’s Eurovision Song Contest. No surprise, perhaps, after his heartfelt lament over the political bias at this year’s competition in Belgrade (UK 14 points, Russia 272).

"Days before the show, I knew Russia would win," he groans. "The fact is, Putin was getting nasty, which meant the former satellite states were always going to vote for Russia in order to keep the oil coming. It’s unfortunate, I suppose, but whereas we have always taken Eurovision with a pinch of salt, the former Eastern Bloc countries are not sufficiently versed in the ways of democracy to realise they are supposed to be voting for a song, not a next-door neighbour.

"The only way the UK will ever regain any respectability is if we get a major British star - Robbie Williams, Take That, God knows there are enough of them - to represent us, and then people will have to vote for us. I was considering giving up before Belgrade, and now I have to say I’m very doubtful about ever wanting to do Eurovision again. I’ve had so much fun, but I think it’s time for someone else to take over."

While Wogan is held in awe by his fellow broadcasters, he has his own favourites. "Obviously, Michael Parkinson was the master of the old school of chat-show hosting, where you actually listened to the people you were interviewing. I love Jonathan Ross, and I believe we have a mutual respect for each other. He’s the UK equivalent of a David Letterman or a Jay Leno, and although he’s not a listener, we don’t require him to be. And Graham Norton is terrific. He does it all with such brio - and in such colourful suits!

"That said, I see an awful lot of presenters who just read out the autocue without any of their own personality and with these awful glazed eyes, like a seagull’s. If you had to ask me which TV presenter I admire the most, for their ability to communicate with the audience, then it’s got to be my old friend Peter Alliss, the golf commentator. For heaven’s sake, when he’s on the box, you think the man’s in the room with you!"

One annual engagement he won’t be giving up, though - "at least not until hell freezes" - is his annual Children in Need marathon. "If you’re talking about high points, then that’s got to be my highest," he says. "Over the years, we’ve raised £480 million for children’s charities, and that makes me very proud indeed. So you see - I did turn out good for something in the end!"