Spandau Ballet bassist Martin Kemp's biggest fear during the band's heyday was that he would end up broke but still famous.

He explores the theme in his debut novel The Game, which features a washed-up pop star from the Eighties, who has lost everything but is still recognised in the street.

"My biggest fear when I was in the band, especially in the middle of the Eighties, was it coming to an end, having nothing left, or all you're left with is a famous face. And people recognising you," admits Kemp, 62.

"I always think, what would happen if you've got absolutely nothing left, but you are left with a famous face? Where do you go? How difficult is it to get back into society? That's the key to the book."

Great British Life: Martin Kemp with his wife, Shirlie. (c) Alamy/PA.Martin Kemp with his wife, Shirlie. (c) Alamy/PA.

Today, the musician and actor lives in a country pile in Hertfordshire (dubbed 'piglet'), has more work than he needs, a happy 35-year marriage to wife Shirlie (of Pepsi & Shirlie fame), and two children - radio presenter Roman, 30 (with whom he appeared on Celebrity Gogglebox), and singer-songwriter Harley Moon, 34.

The novel - a thriller involving London gangsters, drug dealers and an eclectic mix of musicians, with a tabloid hack and a music journalist thrown in for good measure - centres on pop has-been Johnny Klein, who lived a real rock'n'roll life back in the day, welcoming all that drugs, women and fast living threw at him.

He's now broke, has had to sell his home, and regrets the way he treated his ex, with whom he has a daughter.

The name Johnny Klein was the alias Kemp used during those heady Spandau days."He was the name I checked into hotels under, I paid my bills under, he was on my bag tags that followed me around the world," he remembers. "It was always me and him."

The hardest thing of all is to be "famous and broke", he writes.

Great British Life: Martin Kemp with his brother, Gary. (c) Ian West/PAMartin Kemp with his brother, Gary. (c) Ian West/PA

Kemp, though, has never gone as low as Johnny Klein. He doesn't have to catch the bus to work or tap old mates for money. But, he recalls: "In the middle of the Eighties, when the band was at its height with our posters on the kids' bedroom walls, we were spending so much money.

"I knew the money that was coming in was only going to last for a few years. It wasn't like this was money to retire on. And it was a huge fear of mine. What would I do? Where would I go? How do you spend your life hiding your face? The idea for the book is an extension of that."

Since those heady Spandau days, however, he has carved himself a lasting career as an actor and presenter, appearing in everything from the hit movie The Krays to top BBC soap EastEnders, reality shows including Celebrity Big Brother and Gogglebox with Roman Kemp, as well as DJing all over the country.

Great British Life: Spandau Ballet in 1985. (c) PA ArchiveSpandau Ballet in 1985. (c) PA Archive

Spandau reunion tours have come and gone - he says he doesn't want another one - and new projects include a 'mockumentary' sequel to the critically-acclaimed The Kemps: All True, a BBC Two spoof about the Spandau Ballet stars' life and music career, in which he stars with his brother Gary, who wrote the hit songs for the band. He has also just launched a menswear collection with Sainsbury's.

But there have been obstacles he's had to overcome along the way, most notably in 1995 when he was diagnosed with two brain tumours. Kemp needed treatment to remove them next over the following three years, and the long convalescence resulted in a significant period off work.

"I was on the floor. I didn't know what was left or right when I was in the middle of that. And you've got to remember, that brain tumour period lasted for probably four or five years before I came out of it," he recalls. "When I was in the middle of that, things were so dark that I wouldn't relate it to Johnny Klein. It was its own battle."

He says he never got as low financially as his fictional hero, but he wanted to explore what it would be like to fall that hard after enjoying such dazzling success.

Great British Life: Martin Kemp. (c) Shirlie Kemp/PAMartin Kemp. (c) Shirlie Kemp/PA

While Klein's drug habit is well documented in the novel, Kemp has previously said that Spandau was primarily a drinking band, a working-class group from North London who were looking after each other. But he acknowledges there is a lot of him in the character.

"There's a big part of me in Johnny, but there's also a big part of lots of rock stars I have met over the years, from Townshend to Bowie, from Jagger to Iggy, the boys from Quo or the guys from Queen," he writes in the foreword.

He also says fame has its payoffs and upsides, but constant recognition is difficult.

"Fame isn't an easy thing to deal with at the best of times. When you're younger, you enjoy every minute of it, you're bringing it on, you love the idea of it and it's good for your ego.

"The older you get, you realise that fame is just a ticket to be able to get a better job. It's just part of life. It's not as easy a run as everybody would think it is, when every time you go out people are looking at you and pointing, talking about you."

In a recent interview on the Radio Times podcast, Roman Kemp said his father didn't have one friend.

"You withdraw with fame," Kemp admits now. "You withdraw your circle of friends. Yeah, I think I can count my friends on one hand, pretty much, and it's usually my old friends that I started with, within the band, or people I've known since before I was famous."

He leads a quieter life these days, he agrees.

"When I was younger, it was all about the evening and going out - now I'm up at six in the morning, enjoying the daytime in my garden. I'm never happier than when I'm covered in mud, having spent the day doing the lawns and the digging."

He has another novel to write (it's a two-book deal), and will be appearing on TV at Christmas with Johnny Vegas and Peter Davison in a Murder, They Hope Christmas special, as well as the Kemp mockumentary.

He doesn't miss Spandau Ballet any more, he adds, although there was a stage when he did.

"I would have done anything to get it back together. When we first got back together in 2015, that tour was absolutely the highlight in my life because I'd missed it for five years before that, and the way we split up.

"But when I look at Spandau now, if I catch it one day on TV on one of the music channels, if I catch myself or listen to the band on the radio, it's almost like it's not me any more," Kemp reflects. "It's like I'm enjoying it in the same way you would enjoy it or anybody else, that it's part of my history - and that's a far nicer way to enjoy what I did."

The Game by Martin Kemp is published by HarperCollins, priced £20.

Great British Life: The Game by Martin Kemp. (c) Harper Collins/PA.The Game by Martin Kemp. (c) Harper Collins/PA.