He has turned the boy-next-door look into an artform - and a lucrative one at that. In the wake of Auf Wiedersehen, Pet, Peak Practice and, particularly, Inspector Morse, he has become one of television's hottest properties, up there with John Thaw and David Jason. When he left Peak Practice, he is said to have had 40 different TV offers.
But how does he do that? After all, he is never going to rival George Clooney as a smouldering sex symbol and his range is not exactly Grand Canyon-wide. The actor's own assessment is that "I have a relaxation on camera. I watch some performers who are superb stage actors - I name no names - and can see them acting. They're putting in too much effort."
Adrian Bate, producer of The Broker's Man, describes Whately as "everybody's woolly-jumper man. He has this boyishness, and viewers have a great desire to look after him. They think he's a person they can have a meaningful relationship with. Kevin's got a great track record of playing nice guys - apart from the odd smudge on his white suit. Could he ever play a bad guy? Even in Trip Trap [where Whately played a brutal wife-beater], viewers were forgiving him."
Similarly in The Broker's Man, Whately's character has had an affair which caused the break-up of his marriage and pain to his two children, but he's still incorrigibly likeable. "He has a bit of human frailty which I hope people warm to," Bate says. At one point, Griffin's wife (Anette Ekblom) snarls that they'll get back together "when I stop smelling her perfume on your clothes... and then a bit a longer". "I'm still in with a chance, then," he replies, with a trademark 200-megawatt smile.
Al Hunter Ashton, the writer who created the series specifically for his old friend Whately, contends that the actor is "sexy. Women want to mother him. I thought the women who fancy him would just be middle-aged, but they're a complete spectrum." (The piles of fan mail on Whately's desk awaiting reply bear this out.) "He's like the little boy lost you want to help. He could never be a threat."
Whately himself is friendliness personified. He admits to being bemused by the fact that he's a sex symbol. "Jimmy Griffin is not what I'd call a sex symbol," he claims. "I'd call Sharpe a sex symbol."
The actor does concede, however, that it's hard to avoid the Mr Nice Guy tag: "I'm always sympathetic to my characters," he reckons, "even if they're monsters. You've got to be able to get inside them."
Though Jimmy Griffin is a good bloke, Whately claims that he is also "full of failings. Things go wrong for him. He's not a heroic hero. He's trying to pull the threads of his life back together and not succeeding. That was why I wanted to do this."
Whately has just completed another one-off episode of Inspector Morse for screening on ITV in the autumn. Although he has played the plodding Sgt Lewis for 12 years now, Whately in no way feels burdened by him. "I'm stuck with Lewis," he laughs, "but I like that. A lot of my work stems from how established I'd become after Lewis. You've got to be proud of the work you've done. If you say `it's crap', you can't do it anymore."
During the summer he is taking a rare break, going to the Test Matches and looking after his two teenage children while his wife does a job at the Bush Theatre. He doesn't yet know what his next part will be, but the one thing he yearns for is a really tasty baddie. "I'm very aware that villains are the most fun to play," he observes. "But from the type of person I am, it's not easy for me to get away with villains. But if, say, I were offered the part of the Bond villain, then you'd be talking."
`The Broker's Man' begins on Tuesday at 9.30pm on BBC1Reuse content