Nigel Planer is a wary customer. He edges into our meeting at a private members’ club in London without meeting my gaze. Then orders the plasma screen and ambient music to be turned off and selects a different chair from the one I offer. Having folded his 6ft 3in (1.9m) frame into it, he looks at me gloomily.

He is supposed to be talking about his new role as the wizard in Wicked, a new West End musical prequel to The Wizard of Oz, which has been a huge success on Broadway. But his mind is on other things. “I can’t stand canned music. My kids have it on all the time.” This clearly reminds him of a domestic duty and he calls his eldest son Stanley. Stanley is 18 and this afternoon he is in charge of Planer’s younger son, Harvey, who is 7. “

I’m afraid if I don’t ring him and remind him to get up, he will stay in bed.”

I’m tempted to crack a gag about Planer’s eldest son being like his character in the Eighties TV comedy series The Young Ones but then I think better of it. Although Planer has probably not been as high profile since The Young Ones as his co-stars Adrian Edmondson and Rik Mayall, he hasn’t been idle. He has thrown himself into plays, writing novels and self-help books. In the process, quite a lot of angst has come out over the past 20 years, thanks to the complicated rollercoaster of love, parenthood and painful separation that he has found himself riding.

For someone whose markedly conventional background (Westminster School, Sussex University) might mark him out as reserved and conservative, Planer is actually rather radical and clearly not at all hesitant about wearing his heart on his sleeve. He would be the perfect candidate for the BBC Two series Grumpy Old Men. Not because, at 53, he’s particularly ancient, but because he is quite grumpy.

“I’m genuinely grumpy,” he agrees. “And they did offer me a part in the first programme. But I thought it wasn’t going to be funny. So I turned it down.” He sighs. “One of the many fantastic roles I have mistakenly turned down in my career.” Although even he cannot deny that Wicked is a great gig at the moment. Planer cheers up, however, when his roles as original cast members in Evita, Chicago and The Queen tribute We Will Rock You are mentioned.

He says that when people see him, they laugh. Always. “And that’s lovely,” he says. “Unless you produce something serious, and that confuses people. Which is frustrating.” Frustrating for him because Planer was clearly born with an instinctive compulsion to recycle his life experiences before the public eye. And they are by no means all comic ones.

His book lampooning the excesses of the acting profession (I, An Actor, 1987) is great fun, but much of the Planer oeuvre has a serious heart to it. In his twenties, he lived with a psychotherapist almost 20 years his senior but, when he was 35 and in the rather unlikely venue of a disco in Lanzarote, he met Anna Leigh, a 22-year-old model who was to be his first wife and the mother of Stanley. Planer, meanwhile, combined his knowledge of the life of a therapist and his experience of marriage to write two non-fiction books lampooning both institutions: Let’s Get Divorced! (1994) and Therapy and How to Avoid It (1996).

Unfortunately, he was to experience both therapy and divorce first-hand when his marriage collapsed.

With hindsight, these non-fictional comic publications seem grimly appropriate, but Planer clearly still felt that there was more worth mining in the personal bank, and wrote the first of his “divorce novels”, as he puts it, The Right Man (1998). His second novel, Faking It (2001), was also, as one critic described, “about a man in mid-life with relationship wreckage strewn about (him)” but, by this time, Planer was married again, in 1999, to Frankie, an actress. Harvey arrived a year later, but the marriage also ended in divorce.

Faking It was originally entitled The Misandrists, meaning “one who hates men”. Planer was dissuaded from using this title by his publisher, who helpfully pointed out that no one would know what it meant. It’s a word Planer still uses, however. “It’s very interesting,” he says. “Everyone knows what a misogynist is, but no one knows what a misandrist is.”

Does he feel hated as a man? He once may have done. After Anna remarried and left the country with his first son, then aged about 12, his contact with Stanley was severely diminished. Not that it had ever been plain sailing; indeed, after his divorce he found out that the principal custody of a child was at that time almost automatically awarded to the mother, and so he joined the respected campaigning body Families Need Fathers to help push for a better deal for divorced dads.

“We helped to bring in huge changes. Huge. Do I wish those changes had been around when Stanley was small? Bloody right I do.” Stanley now lives with Planer, and has done so for years, although Planer still talks about the experience of divorce with profound sadness.