Looking at him in the light of this new information, it all suddenly seems quite plausible. Yet nobody has ever suspected him and you can understand why. His biggest successes to date have been his studies in emotional vacuity, those beautifully observed alter-egos like the eternally miserable hippy Neil in The Young Ones.
And Planer is such a chameleon, career-wise, that it's difficult to credit a consistent artistic thread. Over the past 15 years, there has been the Number 2 chart hit ("Hole in My Shoe"), the biggish acting roles (Shine on Harvey Moon, Bonjour La Classe), the skirmishes with opera (work for the ENO and Music Theatre London), the self-help book about becoming a father (A Good Enough Dad) and, as if that weren't enough, the voice-overs on the new Magic Roundabout.
"I know what people will say," says Planer. "They'll say: 'Oh God, now he thinks he can do poetry too.' But it's not like that." For years, he says, he has been associated with the generation of alternative comicsthat cut its teeth in the early Eighties and gave us The Comic Strip. His coming out is a sort of belated, two-fingered response to that world. "Peace at last" is how he describes it.
"I wouldn't have dared do this 10 years ago," he begins. "I was surrounded by comedians who were looking at other people's endeavours and thinking: 'I've got an angle on that. I can fire a salvo at that.' Anyone who writes a poem where they say something they really feel in that atmosphere is going to have 90 comedians all going: 'We've got you now, we'll make you look like a complete idiot.' But people who use comedy like that don't really win in the end." He pauses, then lets out a rare chuckle. "No, I take that back. They end up hugely rich and probably much happier." And then, with Neil-like paranoiac emphasis, says: "The bastards."
So Planer has said: "Sod it, why not?" and now he's touring the UK's burgeoning performance poetry circuit with the comic poet and scriptwriter Henry Normal, "learning that you can get a laugh without being nasty". But anyone going along in the hope that he's going to dish the dirt on his former colleagues will be disappointed. Planer says he's not ready to read the poems he's written about his acting life. A lot of his poetry is comic, or rather, self-depracatingly serious, much like his conversational manner. He gives audiences a choice of poems. "I ask them if they want lovely, lovely ones, pervy ones or dysfunctional ones. Dysfunctional wins every time."
The "I" in his verse is often a composite character, a poetic equivalent to his dramatic alter-egos. The voice can range from that of a daughter embittered by her mother's provocative behaviour to that of a sad, middle- aged stud worn out by "bloody life-ruining war between the sexes".
Divorced this year from his wife of seven years, the former model Anna Leigh, Planer has clearly gone through a period of intense reflection in his Chelsea houseboat. He has dug up lines charting domestic pain past and laid them beside more recent material. "Sleeping in My Office" for example, written in 1985, bemoans homelessness after the break-up of an earlier relationship.
"There's a lot about gender roles, I suppose," he grins morosely. "Everyone I know seems to be affected by it. Men who've run off and been complete bastards or vice versa. What constitutes a family seems to be up for debate."
Planer knows that maybe his personality can help popularise poetry, and inch it above the fluffy John Hegley standard. "I hope people will be impressed that I managed to do this," he smirks. "Actually, I'm hoping it'll get me laid," he adds, unexpectedly and unapologetically, as the waitress clears away his plate. "That's what they say, isn't it? Well, it hasn't worked yet." It's difficult, these days, to know when Nigel Planer is joking and when he's being terribly, terribly serious.
n Nigel Planer and Henry Normal perform tonight at Apples & Snakes, 8.30pm, The Civic, 600 Old Kent Road, London SE15 (0171-732 3232) pounds 7/pounds 5Reuse content