Joking apart, he's got a point. A channel starting up with a limited budget could almost certainly not stretch to buying up the most surefire ratings winner in TV drama. No one has better record of hoovering up viewers; from The Sweeney, through Inspector Morse to Kavanagh QC, Thaw has proved the most bankable television commodity this side of The National Lottery Live.
His only failure has been the regrettable version of A Year in Provence - about which he is commendably philosophical. "I had a disaster with that," he admits, "but we're all allowed one. I was saddened because we all worked hard and hoped it would be enjoyed. It was enjoyed - but only by five people. I've had that upset, but I've still been given other work."
Just what is it, then, about this white-haired man of 55, with the grizzled look and the grouchy air, that sends viewers - and commissioning editors - weak at the knees? In person, Thaw has a twinkle about him which goes a long way towards explaining his appeal; when he leans forward and fixes you with his luminous blue eyes, you can see exactly why viewers warm to him. The curmudgeonly exterior also belies a dry sense of humour. He has been known to come onto the set of Kavanagh QC imitating a Regency fop. And when it is suggested to him that Kavanagh seems happier this series, he replies, quick as a flash: "Does he? I'll have to put a stop to that."
But there's more to it than that. "We trust him," asserts Chris Kelly, the producer of Kavanagh QC. "He's a bloke you'd like to have on your side. He's a good man, but life hasn't always been easy for him. He has strength and vulnerability - that's a pretty potent package."
It has also turned him into perhaps the most unlikely sex symbol since David Mellor. "He's an ordinary bloke," Kelly continues. "He's not impossibly glamorous - he's no Robert Redford. But I was lunching with him at the River Cafe the other day, and young women in their twenties were coming over with billets doux and whispers. They were behaving in an extraordinary manner." He adds with a smile: "I was very jealous and sulked a lot."
Ted Childs, who has worked with Thaw on all his big hits and is executive producer on Kavanagh, chips in: "He's the sort of person people would like to have as a father or a lover. He has this great sympathy. Look at Morse. If you read that character on the page, you'd say, `what a miserable sod'. In the wrong hands, it could have become a tedious portrayal. But John is able to make the character appealing. In his hands, Morse is a flawed hero who evinces sympathy rather than disinterest. You want him to win. Frost is like Sam Spade, an alien figure who is capable of establishing a rapport with an audience."
Puffing on the first of many cigarettes, Thaw looks tanned and relaxed after filming Into the Blue, a new ITV thriller, in Rhodes. He is endearingly modest about his success, attributing a lot of it to our passion for crime stories. "The British love crime and anything to do with it," he reflects. "You could put on a series about judges' batmen and it would still get huge ratings. Maybe it's because we were lawless at one time and still are in our hearts. There's also an element of `there but for the grace of God' about these series - not least for me. You think, `thank God that didn't happen to me'."
All the same, he is finding Kavanagh, the wily yet compassionate old barrister, one of his most testing roles yet. "I know I sound like a whingeing actor," he sighs, "but you've got nothing in a courtroom scene to lead on to. I find it fascinating to watch, but when you see it on the page, you can have a dozen questions and if the other person is only saying `yes', `no', or `could be', it really is a memory test. I did suggest an autocue once, but it was quietly given a blank."
He really has no need for such aids, as he is technically so proficient. In Childs's estimation, "John has an intelligent awareness of what an audience wants. I don't want to be too grand about it, but coming from humble origins, he understands the human psyche. He films very well, too - he ought to direct. He understands - in a way not all actors do - the opportunities and constraints of television. He performs well in close-up because he's a minimalist. He resists the temptation to over-play."
Thaw has now reached the status where he can afford to be choosy about his roles. He is sent forest-loads of scripts by hopeful television companies, but reading most of them he thinks to himself, "this is a waste of money. Go and buy thousands of pounds' worth of lottery tickets instead." He will only go for a part, "if I believe it - it's as simple as that. Next to that is, `do I believe that I can make other people believe it?' It may not add up - like some of the Morses - but I think, `can I do it in such a way that persuades people that it does?'."
This can make him a demanding presence on set. "He's good at telling you what's wrong with scripts," Childs affirms. "He's no pushover; he can be tough about things. He interrogates you closely about character."
Kelly elaborates. "He's extraordinarily acute about scripts - not a single nuance escapes him. In one episode, Kavanagh made a leap of logic in court, and John said, `I can't see the link here'. I set off on a pseudo- intellectual explanation, and he said, `Oh, you mean it's bollocks. I can do bollocks'."
Perhaps this is what distinguishes Thaw's performances; the simple matter of putting an awful lot of hard work into them. Thaw says cautiously that "I give my opinion" about the Kavanagh scripts, before revealing how he does it - jokily metamorphosing into Harry Enfield's Self-Righteous Brothers and shouting: "Oi, Chris Kelly, NO!".
`Kavanagh QC' returns Mon at 8.30pm on ITV. Later in the year, John Thaw returns as Inspector Morse in `Death is Now My Neighbour', a one- off film, and stars in a new thriller, `Into the Blue', both on ITV
1942: Born in Manchester, son of a lorry driver
1950s: Left school with one O-Level and went to work in a bakery. Won scholarship to Rada
1974: Big TV break playing tough-nut detective Jack Regan in cop show, `The Sweeney'. Says he would never block its satellite afterlife - as Martin Shaw has done with `The Professionals'. "It's something I'm proud of. I don't see why it shouldn't be shown."
1980s: Successful stage appearances in "Serjeant Musgrave's Dance" (National Theatre) and "Henry VIII" (RSC)
1987: Played creepy police chief in Richard Attenborough's biopic about Steve Biko, "Cry Freedom"
1987-97: Title role in ITV's top-class adaptations of Colin Dexter's "Inspector Morse"
1992: Title roles in TV screenplays, "Bomber Harris" and "Stanley and the Women"
1993: His one slip-up, the BBC's critically panned version of "A Year in Provence"
1995: Repeated his acclaimed stage performance as a failed Labour leader in the BBC's reading of David Hare's "The Absence of War"
1995-7: Title role in ITV's high-calibre courtroom drama, "Kavanagh QC"Reuse content