here are two things everyone admits about Phil Collins: that he is a workaholic addicted to performing, and that he is a genuinely nice guy, so lacking in enemies or private scandal that the Daily Star was once re-duced to the headline, `Faultless Phil. Mr Perfect. By His Mom'. The former description helps explain his tremendous suc-cess; the latter could have undermined it, for stories of drug-taking and wrecking hotel rooms are among the tools of self-publicity. But it's in his favour that pop music no longer hangs upon notoriety. In baggy trousers, sneakers and Fair Isle pullies, Collins exudes a sensible, sparky presence, just right for one of the Princess of Wales' favourite pop stars.

No one can doubt he has earned his stripes. The former Led Zeppelin singer, Robert Plant, one of many rock stars who have called upon his services as a drummer and producer, says, `I'd like to put my arm around him, walk him down the road to the pub and say, "Just relax a bit."'

No chance. At present, for example, Genesis, in their twenty-first year, are approaching the end of a world tour which has earned them $300, 000 a night in America. In the six-week break they have allowed themselves mid-tour, Collins has been persuaded to play drums on his great friend Eric Clapton's American dates. Then, after Genesis' last British concert, he will prepare until October for his first major film role in Buster. Next year is set aside for his fourth solo album and its promotion. To his credit, Mr Perfect is honestly amazed by the insatiable public demand he generates.

Now 36, Phil Collins began as a professional drummer in the mid-Sixties, playing with transient London bands like Flaming Youth. He always expected not stardom, but the lot of a jobbing musician, ending his days in a West End orchestra pit.

In 1970, Tony Stratton-Smith, a sports journalist turned record company owner, pointed him towards the fledgling Genesis, who were signed to his Charisma label. Collins, the breezy pro, joined a devout bunch of ex-Charterhouse schoolboys playing art-rock: airy, rambling LP music, with titles like The Grand Parade of Life-less Packaging, demonstrating a fastidious distaste for commercialism. The typical fan, he now reflects, was a spotty bloke from Manchester with a fishing hat, a long coat and a bunch of albums under his arm saying, "Can you sign this, Phil?"'

Their most obvious asset was the enigmatic singer and lyricist, Peter Gabriel, intense and theatrical on stage, intense and tongue-tied off it: a split personality which his partly-shaven head seemed to symbolise. However, Genesis were not big sellers and there was pressure within the record company to dump them.

When Gabriel left in 1975 to make experimental albums on his own, he appeared to be taking away with him the hopes of his colleagues, as well as their resentment of his disproportionate influence. That Genesis without him eventually found a greater musical purpose was due in large part to Collins' single-minded self-improvement. Previously, perhaps, the least considered member, who wrote little and sang only one song, he spent several weeks making demo tapes of his voice in order to convince the dubious he should be the new singer.

Remarkably, he sounded very like Gabriel, an argument which defeated 400 other applicants, as Stratton-Smith recalls: `I don't think there was a single vote in favour of Phil initially, but that changed within six weeks. As far as the writing went I took the view - as, I suspect, did other members of the band - that Phil might not be adequate. As regards the singing, I had an extraordinary feeling that we were doing something a tiny bit dishonest, in that Phil's voice sounded so similar to Peter's. I think Phil was a far more skilled actor than anybody had given him credit for, and sitting and playing behind Peter for so long, there was a kind of unconscious wish to do it the way Peter did.'"

Stratton-Smith, who has since sold Charisma to Richard Branson, wonders whether Collins would have become as successful had Gabriel stayed with Genesis: "I think it would have been a lot more difficult." But he agrees that Collins' 'common touch' and robust gift for entertainment made Genesis easier to market. "In the long term, the only thing the band lost was Peter's mind. But I believe that was a very substantial loss, and perhaps made the difference between Genesis being a world heavyweight champion for life and just a very good heavyweight champion."

Starting with A Trick of the Tail in 1976, Genesis responded to Collins' prompting by gradually shedding their cult appeal and easing into the popular mainstream. Their records became more concise and straightforward. Follow You, Follow Me in 1978 was the first of many hit singles. Invisible Touch, their most recent LP, has already sold 5,000,000 copies. Collins anticipates at least one more album, though Genesis will probably never tour for so long again.

He and the two surviving founder members, keyboards player Tony Banks and guitarist Mike Rutherford, now control 27 companies between them. In 1981 they bought a farm with 40 acres near Guildford in Surrey, and turned the cowshed into an ultra-modern studio, with accommodation for themselves and their road crew in the farmhouse. All three have large houses nearby, and pop in and out. Their relationship is apparently better than ever, even though Banks, whom Collins acknowledges as the 'basic backbone' of Genesis, is disgruntled by the suggestion that Collins is responsible for their popularity.

This camaraderie, essential to a group's survival, has been seriously imperiled only once since Gabriel's departure: by Collins himself, forced to choose between the band and his first wife's ultimatum to stop touring. Andy was a singer in his school band, the Real Thing, but they did not marry until 1975, when she already had a daughter named Jolie. Collins continued touring, and in 1978 their marriage collapsed after her affair with their decorator. Andy emigrated to Vancouver with Jolie and their son Simon, now nine (and another drummer). Both children return for the summer holidays, the one permanent space in his calendar. His second wife, Jill Tavelman, a petite schoolteacher he met in Los Angeles, now travels everywhere with him.

By the time of their wedding in 1984, Collins' solo career was in resplendent flight; ironically, it owed everything to the failure of his first marriage. Face Value, the LP which in 1981 launched him on his own, released unhappy memories. On In the Air Tonight, now his signature tune, he sang: 'I was there and I saw what you did/I saw it with my own two eyes/So you can wipe off that grin/I know where you've been/It's all been a pack of lies.' Composed as therapy, the melancholy Face Value was an instant hit.

The next albums, Hello, I Must be Going and No Jacket Required, recollected his first love for soul music, notably Motown, and he began to win a black following with his version of the Supremes 'You Can't Hurry Love and his duet on Easy Lover with Philip Bailey.

He was suddenly everywhere on radio and television, in several guises. He was nominated for an Oscar for the music he composed for the film Against All Odds, and played a sleazy game-show host on Miami Vice. And women had discovered him, found him 'cuddly', and were throwing teddy bears on stage. His famous Live Aid feat, appearing via Concorde with Sting in Britain and Led Zeppelin in America, reflected his galloping confidence and willingness to have a go. On every count he has success-fully negotiated the long and difficult journey from rock obscurity to showbiz stardom.

"He'll be happy in showbiz, of one form or another, for the rest of his life," says Peter Gabriel, still a friend. "The rest of us in Genesis were anal retentives, I think. He was a little more liberated, always at ease with the media." After a decade of critical applause but few hits, Gabriel himself is sunning in the popularity of his recent, most accessible, LP called So, which also shows an obvious soul influence. But he rejects the view that Collins' fame has been his spur, or that competition exists between them, even though both were entered against each other at the British Phonographic Industry Awards in February (Gabriel won). "The world is always winding one or other of us up because we have both done the same gig," he explains gently. "Phil is a great natural musician. There's a lot of my stuff which is hard for people to stomach. I think most of Phil's is easily digested."

That is precisely the problem for Collins, who reads all his reviews and feels he suffers from the public comparison. "I don't receive the benefit of the doubt; Peter does. I don't lower my sights so people will buy my records, but I believe people think I do. I love what he does. I just wish they didn't think he's the artist and I'm just the pop star. I'd dearly like the kind of respect he seems to have. I get it from musicians and punters, but I guess it's the press, and I don't know whether I should be bothered about what the press cares to think."

Stumped for an angle the press, indeed, has homed in on his unglamorous appearance. He wearies of comments about his receding hair-line or lack of height (`I'm 5ft 8in, okay?'). Rolling Stone dismissed him as a `Cabbage Patch Kid for the pop audience'. Julie Burchill rummaged deeper in her bag of insults and came out with `The ugliest man since George Orwell'. That hurt as much as it puzzled: `How ugly was George Orwell?'

His evident vulnerability is unusual in the profession of pumped-up egos, and this personal modesty. extends to his lifestyle, which is not profligate, despite having reputably sold 15 million solo albums and earned £22,000,000 in 1985 alone. His car remains a W-registration BMW - though it is a 7-series. "I've got money,' he admits, laughing, "but I still live like I haven't."

As to exactly how much he's worth he simply hasn't a clue. According to his accountant, Collins really couldn't care less about wealth as long as he pays his taxes. He owns one house and some tax-free woodland in Scotland, but he has no overseas investments. "I work so that I can enjoy money and don't have to think about it," he says.

His hobby is collecting tin toys, like Dinkies, and car mascots. "Bumpers and radiators, too," he chuckles. "It's like Steptoe and Son, our house." In his free time on tour he and Jill, who collects powder compacts, scour the junk shops. "You can pay £500 or more for a good tin toy in the original box," he confides knowledgeably, "but I don't do that, because half the fun is to find a bargain. And I'm pleased with that. I think, "Don't change, boy", 'cos maybe that's what makes you different."

His mother, June, who ran a toy shop before becoming a children's theatrical agent, confirms her son's unspoiled nature once again. Still active in her 70s, at the Barbara Speake stage school in west London, she says: "I'm as amazed by his popularity as he is. I'm glad I'm not Boy George's mother. Of course, Phil may have taken drugs sometime, but I've never seen him or even known." Collins himself was a pupil at Barbara Speake's school. For seven months he played the part of the Artful Dodger in the West End run of Oliver!, and later enjoyed being an extra in A Hard Day's Night, but he has always preferred music.

He is, fundamentally, a music fan. Recalling Clapton albums he has produced, he says, "The first time I put my finger on the control button and said, "Do you want to do that guitar solo again?" was a big moment.' That he has also produced Adam Ant and Frida (ex Abba), turned down Barbara Streisand and Liza Minnelli through lack of time, and agreed to do jazz drummers Buddy Rich and Tony Williams, indicates the extent of his taste and the esteem of his peers. His ambition is to produce Aretha Franklin and Steve Winwood.

Playing other people's music is basically his relaxation. "I don't ever do nothing," he cheerfully confesses. "At home I'll sit and wonder what I should be doing." But Peter Gabriel, whose own marriage suffered from his over-work, offers a more penetrating explanation of his restlessness. "People achieve in life, positively or negatively, according to what their psyche pines for."

Collins believes he could still be performing his own, if not Genesis', music at 46, without 'going Vegas'. But it may well be that acting will lure him back, despite his insistence that Buster is a one-off. Having turned down many scripts, he liked the idea of a romantic comedy about the havoc wreaked by the Great Train Robbery on the marriage of Buster Edwards. He did it because Julie Walters also agreed.

He is typically open about his qualms. "I do wake up some mornings in a cold sweat. I mean, I was only a kid when I acted before." He also worries that his real wife will accompany him to the set. "I don't think I could be somebody else if she was around," he agonises, "and Julie's playing my wife, after all. I'll have to flirt. Jill's already asked if there are any "bits" in it. I've told her not really, not at the moment."' David Green, the director, had no hesitation in choosing Phil for the role. "I'd seen his performance in Miami Vice and was bowled over. He's perfect for the character of Buster, similar in both age and looks. But more than that he's a genuinely warm family man, happy go lucky and with a great sense of humour."