Forty years ago, crossing Michael Franzese was a very bad idea. In fact, it could have been a life-ending one.

Because for many years he was a Mafia boss of the Colombo crime family - one of the five most powerful gangs that ruled New York's underworld.

At the peak of his notoriety he was earning a staggering $8million a week through a fuel tax fraud.

In 1986, the US magazine Fortune named him on their 'Fifty Most Powerful and Wealthy Mafia Bosses'. Vanity Fair said he was "one of the highest earners the Mob had seen since Al Capone". Little wonder then he was coined 'Prince of the Mafia'.

He served two spells in prison - by the end of which he made a life-changing decision: After finding God while behind bars, he decided to quit the Mob.

With contracts out on his life - including one approved by his own father - he took his family and fled the Big Apple. In doing so, he became the only head of a major crime family to walk away, without police protection and survive.

It is a remarkable life which, on Sunday, will see him visit Kent.

Appearing at the Mercure Maidstone Great Danes Hotel, it is one of the first dates on a speaking and Q&A tour of the UK in which he promises to spill the beans on just what life was like as the head of one of the world's most glamorised crime syndicates.

"I've been speaking for 24 years now," the now 71-year-old tells KentOnline. "I've spoken to people in prison, people in boardrooms and everyone in-between. Fortunately for me there is an intrigue or a fascination in the Mob genre. People just want to hear the truth about that life. They associate it with movies and I just fill in all the blanks for them."

From the Godfather to Goodfellas (in which Franzese is portrayed by Joseph Bono), to Gotti and The Irishman, our appetite for the often brutal blend of business, crime and money-making appears undimmed over the years.

The questions he faces, inevitably, tend to be familiar.

"They always ask where Jimmy Hoffa is buried - every country I've been in they ask that question," he says of the truck drivers' union boss whose disappearance has been the subject of much debate over the years, "where all my money is and have I ever killed anyone - those always come up. Then they'll ask about John Gotti (boss of the Gambino crime family in New York) and various things within the Mob.

"But many times the focus is on my personal life - my family and my transformation. People want to know how I got out of a bad situation and survived. They'll ask 'how difficult was it for you, mentally and emotionally?'. It leaves me to believe that in some ways we're all the same; we're all struggling in some way.

"Many of us had to come out of a difficult situation. I think people find it intriguing and encouraging that I've been able to escape that life and live a normal life."

We'll come on to that hot potato of did he actually kill anyone in a moment.

Today he is a motivational speaker who is happy to discuss the grittier side of his past life. He doesn't look 71 and as we chat is relaxed, warm and friendly. It's hard to equate him with the criminal life he once led.

So just how does he speak to youngsters in jails or starting out in a life of crime who will, inevitably, regard him and his 'success' within the Mafia with some awe?

"I have a lot of credibility because people look at the Mafia as the biggest and most organised gang in the world - and in many respects we were," he explains.

"The fact I've lived that life, gotten out of it, and been able to lead a normal life and go on and have some success, means a lot to people.

"But I have to caution these young people. They do say to me, 'Mike, come on we saw the movies, you had it all, you had the money, the cars, the women, power and respect - and I say 'yes, but did you not see the end of the film? Those who died, who went to jail, who lost everything'.

"That's how it ends all the time. Then I'll go down the list of the 50 biggest Mob bosses that I was named on in 1986 and 48 of them are dead. Many died in prison, some were murdered. There's only one left besides me and he's doing life. I'm the exception not the rule.

"I bring these kids down to earth. I let them understand - you're going to spend the rest of your life in prison because if you continue that's what you've got to face. Either that or the cemetery."

It's a fascinating tightrope he has to walk. There is no getting away from the fact the Mob has been glamorised by Hollywood - depicting sharp-dressed, sharp-talking crooks who carry off crimes with a certain swagger.

"I never glorify the life," he stresses, "I call it an evil life as I don't know any family involved who haven't been totally devastated - including my own.

"I spared my wife and children that, but my mother, father, brothers and sisters had a devastating life. And it's true of every family of every member of that life that remains within it.

"When a lifestyle does that to a family you have to call it bad or evil and I make that very clear.

"However, I'm not saying every guy in that life was bad, every day was bad or everything we did was bad. We obviously engaged in criminal activity quite a bit, but there was a lot of good sides to the life too.

"People want to hear both."

And he's aware the UK is far from exempt in terms of idolising criminals.

"I was also in Shoreditch last time I was here," he explains, "and they've changed the court house into a hotel (now the swanky five-star Courthouse Hotel) and they have two areas in there that were formally cells that they housed the Kray twins in. I'm very familiar with them.

"I loved Peaky Blinders - I watched the whole series - I was very intrigued by it, so I know you have your element here too."

Born into the business - his father was underboss Sonny Franzese - he originally had no plans to follow his father into the firm - nor was he encouraged to. But after his father was jailed for 50 years in 1967 for masterminding a string of bank robberies, he pulled out of university to help his family.

After visiting his father behind bars, Sonny asked him: "If you ever had to kill anybody, could you do it?’

"I said, ‘Dad, if the circumstances were right I think I could’.

“He said, ‘That’s the right answer. Go home. I’m going to send word downtown and somebody will be in touch with you. You do whatever you are told’.

“That was it. That’s how he prepared me."

Brought in as recruit for two-and-a-half years, he finally under went the 'made man' ceremony in 1975. Key to it is the omertà - an oath of silence forbidding you from every revealing its secrets on pain of death - not to mention pledging to do whatever ordered to do by the Mob bosses.

Quickly rising through the ranks, by 1980 he reached the level of caporegime - the rank of captain - in charge of 300 men.

Soon after, he became involved in a scheme to defraud the US government out of gasoline taxes. The scam, which saw him supply hundreds of filling stations, without paying tax, was a huge cash cow. The supplies he was involved in reportedly covered up to a half of all fuel sold in New York. Franzese said at its peak it was generating $8m a week.

Such was the scale of the money making, during one trip in a helicopter over the city he threw $25,0000 out of the window and into the happy clutches of the unsuspecting public below.

However, it would also prove his undoing.

Sentenced to 10 years in jail in 1986, when the authorities finally smashed the racket, he was also ordered to pay back millions. He served just under four years.

Arrested again in 1991 for violating his parole terms, he returned to jail.

It was there a guard passed him a copy of the Bible and sparked his transfomation - helped in no small part by his wife Camille. The two have now been married for 37 years.

Upon his release he gathered his wife and children and disappeared to California - a move which led to contracts being taken on his life. Incredibly one would have had to be approved by his father who would eventually serve 40 years of his term before being released when he hit 100.

He admits his father's approval on the death sentence hurt him - but understood how the Mob worked and that, by failing to approve it, his father's life would have been at risk too.

It was in California father and son were finally reunited.

He has, therefore, got used to always looking over his shoulder. So just how did he cope with a fear which would topple many others over the edge?

"I spent 20 years in that life and during that there were times when I was fearful," he admits. "Not scared to where I was ready to cut and run, but fearfully cautious of things.

"I saw guys around me that got killed.

"One of the dangers and horrors of that life is you make a mistake, and your best friend walks you into a room and you don't walk out again.

"Obviously I've experienced that with others. I had that situation myself so there's a lot of bad stuff in that life. You're always on your toes, always cautiously fearful.

"If you make a mistake, and your best friend walks you into a room, you don't walk out again..."

"So when I get out of the life, I think they're not going to do that to me. They're not going to walk me into a room, they're going to have to try and get me.

"So I didn't have that same fear.

"I thought I was going to protect myself and not worry about it. It meant dealing with fear happened during that time in my life not after it.

"My fear comes from, God forbid, if anything was to happen to my children, my grandchildren. I fear like normal people fear. But I don't have a fear of people on the street at this point in time."

He says he remains cautious when he returns to New York ("I don't run around telling everyone 'hey, I'm here I'm back in town'. I believe in God and God doesn't tell you to be stupid. You have to use your head. I'm always very aware of my surroundings") but having kept his mouth shut in jail and refusing to "bad mouth" his former associates, he hopes the threat has finally subsided.

So did he ever kill anyone?

He's suitably vague in his answer ("you are told what to do and you got to do it") but even if he hasn't he was likely involved in such crimes albeit not directly.

How, I wonder, does his past sit with his committed Christian faith?

"The basis of Christian faith is sincerity," he explains. "If we sincerely confess our sins and accept Christ our sins are forgiven.

"People say to me 'Michael, do you do what you do to make up for what you did in the past?'. And I say no - I can't make up for what I've done. What I've done is done.

"I always tell people who will listen that I will be judged one day.

"I've pulled a lot of frauds on the streets during my time - and I was good at it, I'll be honest with you - but you can't pull a fraud on God. He knows our hearts. One day I'll either be rewarded or penalised for it. I'm very aware of that and I try and live my life accordingly."

An Evening with Michael Franzese - the Real Goodfella - takes place at the Mercure Maidstone Great Danes Hotel starting at 6pm on Sunday evening. Tickets - which include a number of VIP options - are available by clicking here.