The lascivious way Phillips says "Hello" epitomises the actor's enduring appeal. He is our Greatest Living Smoothie, the embodiment of all we hold dear about the charming cad. Thanks to all those endlessly repeated Doctor and Carry On films, he has been saddled with the image of the mischievous rake. Try as he might, he can't escape being pigeonholed as the ultimate moustache-twirling playboy - all cravat and convertible sports car - who is never more than a nudge or a wink away from the next double entendre. No one has ever injected such apparently harmless phrases as "ding-dong" or "left hand down a bit" with more unwarranted innuendo.
In his shady west London garden, we chat over the coffee which he has spent fifteen minutes lovingly preparing - "French Roast. Good, isn't it?" Sweeping back his still luxuriant, sandy hair, he ponders why the louche image has stuck. He thinks it has something to do with his naturally suggestive voice.
"That cad figure was a loveable bastard, wasn't he? I still get admiration from both sexes. Just yesterday, a woman with a pushchair stopped me outside my house and said, "My mum and I have always watched everything you do. We think you've got the most beautiful voice. It's something we love to listen to." I don't know where my voice came from - I was born in Cockneyland (Tottenham, to be precise) - but it is my most useful asset. If I ring a bank or an insurance company, I don't have to say who I am; they always recognise me instantly. I can get that special quality into any word. It doesn't have to be `hello'. I can do it with `goodbye' too."
Now aged 75, Phillips still looks the part of the roue - the moustache is beautifully manicured, the buckles on the suede shoes are polished to a high sheen, and three buttons of the snazzy striped shirt are undone, revealing two glinting gold necklaces nestling in lush chest hair. But he is tired of playing the role of the nation's favourite Lothario, cultivated in such deathless works as Not Now Darling, Don't Just Lie There, Say Something! and Casanova 73.
For the past quarter of the century, he has been desperately trying to shed the tag of a lightweight lecher not safe beside a woman on a sofa. "That MG-driving image has stuck because it's been exploited around the world - I've made more movies than anyone else in Britain, you know. If I hadn't been able to bridge that gap, it would have concerned me. It did worry me 25 years ago when I was longing to play serious roles and the cad roles still dominated. After I'd made the switch - the first positive decision of my life - there was a lean period to begin with. Directors only wanted me to do the old stuff, and my bank manager got worried. But when I finally broke through into more serious drama, it was electric. Everyone said to me, `I didn't know you could do all that'."
He has now well and truly proved that he can. Over the past two decades, Phillips has notched up roles in such substantial films as Sydney Pollack's Out of Africa, Steven Spielberg's Empire of the Sun and Anthony Hopkins' August. He has also appeared in meaty theatre productions such as The Cherry Orchard, Passion Play, Camino Real and Love for Love. Two years ago, he gave an acclaimed Falstaff in the RSC's Merry Wives of Windsor.
Now he can add to that list On the Whole It's Been Jolly Good. Peter Tinniswood, who won a Fringe First last year with The Last Obit, has penned this touching one-man play about Sir Plympton Makepeace, an MP unceremoniously booted out of the House of Commons after 60 years of undistinguished service. In a bravura solo performance, Sir Plympton surveys the futile decades he has passed on the back benches, most of which now seem a bit hazy. "That woman with the loud voice," he muses. "I think she was Prime Minister, but to me she looked like a power-mad swimming baths attendant."
Phillips says he warmed to Sir Plympton's attitude towards his job. "This is a man who became a politician almost by accident. He never really wanted to be one. Although he's been in politics for 60 years, he's avoided it very cleverly. If he'd been as clever doing it as not doing it, he could have been Prime Minister." The actor clearly relishes the role: "All I've got to do is remember the bloody thing." Not only is Phillips undertaking the memory test of an hour-long, one-man show when he is ten years past collecting his bus pass, but he is doing so under the unforgiving critical microscope of the Edinburgh Fringe. As if that wasn't enough of a challenge, it's his Fringe debut, too.
"It's demanding and daunting," Phillips says with a laugh which betrays fear as much as humour. "I'm not exactly 25 anymore. Recently I've been saying to myself, `Why the hell did I agree to do this?' At the same time, I think, `If I can do this, I can do anything.' As one gets older, one thinks one should go easy, but I still can't resist these challenges. We're not talking about contributing to the pension fund here, but contributing artistically by doing something daring."
Phillips makes for engaging company. He may suffer from a severe dose of anecdote-itis and he is barely on first-name terms with modesty, but he simply enthuses all those he meets with his sheer lust for life.
He chortles wickedly when informed that many see him as a national institution. Then, more sombrely, he reflects: "Every few days someone I know dies, and that affects me. I see their obituaries and often think, `What will they write about me?' I bet they'll concentrate on the early Carry Ons. I've broken away from that sphere, butthey're always on bloody TV. Somewhere in the world, I'm on every night."
For all that, Phillips has no intention of stopping. Indeed, he has recently been working opposite Brenda Blethyn on a film called Saving Grace, and is hoping Anthony Hopkins will fulfil a promise to direct him as King Lear. Meanwhile he is restoring a 200-year-old farmhouse in Spain.
"I've kept working for an inordinate length," he smiles. "I don't think there's anyone else of my age still going who's got their marbles. But retirement is not a word that comes into one's vocabulary. Old actors are like soldiers: they die in action."
So he won't be practising saying "goodbye" for a while yet.
"On the Whole It's Been Jolly Good" is at The Pleasance (0131 556 6550) until 30 Aug