There are 20 odd miles between Salford and Wilmslow. Just over half an hour in a car if the traffic in Greater Manchester is light. Not so very far really, if you’re talking geographically.

But biographically? How does Russell Watson measure the gap? Close enough for comfort perhaps for a Salford lad, but far enough to measure the distance between the man he was and the man he is.

Watson is the former factory worker and Manchester United fan who worked for 10 years in the working men’s clubs before singing Nessun Dorma at Old Trafford in 1999 and becoming the classical crossover act par excellence, a multi-platinum selling artiste (as he’s quick to remind me), a man who has sung for a pope, the Queen and three US presidents (four if you count the time he performed in front of Donald Trump years ago). He’s also a man who has survived not one but two life-threatening brain tumours and duetted at various times with Cliff Richard, Pavarotti, Lulu and even Shaun Ryder (I am not implying any equivalence, by the way).

It is Friday lunchtime in Wilmslow and the Watson household is full. Watson’s sister (and manager) Hayley is talking to Chris the photographer. Watson’s wife Louise is nearby and I am sitting in the kitchen chatting to Becky, Watson’s older daughter and PA. It’s very much a family business these days. Becky is telling me how excited she is about her first trip to New York tomorrow with her dad.

On the shelf near where I am sitting there are four Brit awards. On the wall there are family photos and pictures of Watson meeting Pope John Paul II and Watson meeting Elton John. There’s a piano in the hall and half a dozen cars in the drive, including a McLaren (according to Chris. I am so not a petrolhead). I’m presuming they can’t all belong to Watson.

At our feet there is a rescue dog. A couple of weeks ago she was thrown from a car on the motorway. She is looking remarkably chipper given the circumstances. There are another two dogs, a duck and a few chickens out in the garden.

And here is Watson, looking pretty chipper himself as it goes. Now aged 50, it’s been 10 years since he underwent surgery for the second tumour and he has regained something of the baby-faced appearance he had before (though I’m not sure he’s convinced of this).

We retreat to the front room to talk and he spends the next hour and a bit entertaining me. In that time he impersonates nearly everyone whose name he mentions (putting on an American accent, an Irish accent, a Salford accent and even a Scottish accent when appropriate) and sings snippets of everything from Nessun Dorma (of course) to Buddy Holly’s Rave On.

He clearly enjoys storytelling. He’s good at it too, with an eye for the killer detail. Here he is describing his first agent: “Proper Salford bloke. Sovereign rings and slicked-back grey hair and a few little yellow streaks because he was on about 50 Woodbine an hour …”

Watson is about to tour to support his latest album True Stories, in which he sings arias, show tunes and his own songs accompanied by Ennio Morricone’s 75-piece orchestra and musicians who have played with Blondie, Portishead and Oasis. Next month he will be singing songs from it in Glasgow Royal Concert Hall with a full orchestra.

Who’ll be there to see him? Women, mostly. “Even in an audience that’s mixed the male percentage would probably be around 30,” he says. “Sometimes I can see in the audience a couple of blokes who clearly look like they’ve been dragged out by their wives and don’t want to be there.”

He remembers once singing on a match night during the World Cup. He even asked the audience who would rather be watching the football, “and all the fellas raised their hands”.

What about you, Russell? Did you put your hand up too? “I did, yeah.”

The Salford lad he was is never far away, really. I suspect that’s an issue sometimes. In conversation he can be bullish but you wonder if that’s just the other side of the coin to insecurity.

When he first came to national prominence, back in 2000, and started turning up in studios with orchestras, he could be intimidated at times. “I very much felt a sense of class divide. I felt like I was this little rag-arse from Salford who had been thrown into this world that I didn’t particularly understand very well. I felt like I had landed on my feet and got lucky, especially when I released the first record and it went to number one in the classical charts and stayed there for a year, which turned out to be a world record.

“At the time I did feel a sense of: ‘My God, I’m here with the Royal Philharmonic Orchestra in George Martin’s studio and looking round thinking: ‘I shouldn’t be here.’”

As a result, he thinks, “maybe sometimes the orchestra viewed me as a bit aloof because I didn’t know how to respond to being with such a level of musicians.

“But I would say that over the last 17 years I’ve not just sat on my arse. I’ve probably done more studying in the last 15 years, more study on the voice and the vocal structure than most people would do in music college in five years.”

Does he feel he’s now got to a point where there is respect? “Somewhere like Italy or America or Japan I’m not judged on my background.” And here? “I think there’s a little bit of sniffiness.”

Watson’s “rag-arse” to riches story isn’t overplayed. He left school at 16 with a CSE grade one in English, went to college where he “p***** around” for a couple of years and then blagged a job in a factory. Precision engineering. Life there sounds very Arthur Seaton.

“It was a production line. You’d have the lathe and pieces of metal here.” He indicates an imaginary tray to his left. “And you’d put them in the lathe. It would spin round. Polish, splash, drop in the side. It was the most mind-numbingly boring job ever.”

Music was to be his escape. It was Watson's grandmother who got him interested in classical music in the first place. She would always be playing Chopin and Schubert when he visited her. At home it was more Cliff Richard and Meat Loaf.

Watson was in a band in his teens. The Crowd, they were called. Half a dozen mates. They did covers of Green Onions and the like. “I played the Casio keyboard with one finger. Never really had the confidence to step up and sing.”

But his mates knew he could and eventually coaxed him to sing in a competition in a pub. He gave the audience a bit of Neil Diamond. Love on the Rocks. He won. Soon he was in the grand final of Piccadilly Radio Search for a Star. He won that too. That’s when the agent approached him and and he started playing working men’s clubs for £55 or £65 a gig.

For the next 10 years he did the circuit, supporting a wife and two young children. “Bloody hard work. And remember it was the 1990s, so it was during the recession. We were absolutely broke. We nearly lost the house three times. In the street we were living on there were repossessions left, right and centre. It was a really tough time.”

He also had to learn his trade. He stands up to show me what he was like when he started in the clubs, giving me a rendition of Rave On as sung by a church mouse.

“I had no idea of any kind of stagecraft or movement or interacting with the audience. I spent a very long apprenticeship where I developed as an artist and an entertainer, something which is sadly lacking these days. Fame is so immediate these days particularly with [TV ] talent shows.

“I think that we have become obsessed with discovering new talent. Once we’ve discovered it, then what? It’s all very well discovering talent but nurturing it, making it grow?”

Did you feel nurtured, Russell? “No. I had to work bloody hard. One of the things about the music industry is in relative terms achieving success, attaining success is difficult but not impossible. Sustaining success, holy s***. Hard work. You have to be a driven lunatic.

“If you can’t take getting kicked in the balls every other week the music industry’s not for you.”

Well quite. But where did that ambition and drive come from? He says his sister Hayley has always wondered that. He didn’t show it as a younger man and it wasn’t instilled by his parents, who were too busy giving him a happy childhood. And yet after the years in the working men’s clubs he transformed himself again into the aforementioned multi-platinum selling artist singing Ultravox songs and Verdi arias and finding a huge audience for both.

Success had its costs. He separated from his first wife Helen shortly after he signed his record deal (he once said it had been "a warring marriage and a warring divorce"). But the rewards are all around us this afternoon.

And yet how fragile a thing it is. A few years after the release of his debut album The Voice, Watson started suffering from pounding headaches. Some weeks before he was to travel to Los Angeles to record an album in 2006 (“coincidentally called That’s Life”, he points out mordantly), he went to see a specialist who told him he was stressed out and needed to relax.

Instead he got on the plane to California to record the album in Capital Studios. But in the meantime the headaches had got worse and worse, his vision had deteriorated and he felt dreadful. “I did actually feel like I was dying,” he admits.

He went to see another specialist at Cedars-Sinai hospital in LA. He tells the story with humour, making the specialist sound like a B-movie actor. “It was so American the way it happened. He was sat on one side of the desk and he went, ‘Mr Watson, you have a tumour … And from the results I’m getting, it’s a very big one.’

“I said, ‘I feel like I’m going to die.'

"He said, ‘There’s nothing like knowing you have a tumour to make the tumour seem worse.’

"‘Oh well, I’ll just go and have a bath then.’”

But you can’t get past the reality of that diagnosis, can you? “When you hear the words 'brain' and 'tumour' in the same sentence, it’s a very big one,” Watson admits. “I had this total and complete out-of-body experience where who I was … who I am … left the building and what was left behind was a completely and utterly dysfunctional shell.”

He was far from home, far from family, in pain and in fear. Perhaps it’s no surprise that he did consider suicide for a moment. “I was at the Beverly Hills Wilshire, stood on the balcony.

“My head was banging so hard and it wasn’t a case of: ‘I can’t deal with this.’ It was a case of the pain. ‘I just want the pain to stop.' I just thought, ‘You know what? I feel like flying off the end of this balcony and ending all this.'”

There is a silence in the room for a moment. “But needless to say I didn’t,” he continues.

He came through surgery only for another tumour to be found a year later after it haemorrhaged in four different places and he had to be rushed to intensive care.

Surviving that wasn’t by any means the end of the ordeal. He had radiotherapy to go through too.

“The radiotherapy destroyed me. I would say that it took me five to six years until I started to feel like a human being again. It took a long time.”

Who were you in those years then, Russell? “A vision of my former self. It was difficult. Because I was a fine specimen of a human being. I worked out. I trained. I had a full head of hair. I was slim. I was ripped.

“But after being walloped by two brain tumours and then 25 blasts, six weeks of radiology and steroids, I’d ballooned to five stone over what my weight should be. My face had ballooned up, my hair had fallen out in chunks. I looked like Friar Tuck."

He points to a mirror in the hall. “I remember I came down the stairs this particular morning and the reflection of what I saw back was completely unrecognisable. There was a picture on the side wall. I looked at the picture and I looked at my reflection and I went: ‘I’m finished.’”

He picks up his phone to find a picture of himself in those years. In it I see a man who looks puffy, who looks overweight, but nothing worse than that. You don’t look terrible in that picture, Russell. “I think I look f*****.”

So, how do you get back from that? “Here’s the driven lunatic in me. The day after I finished radiology the lady who was head of the department came over and she said, ‘Now, Mr Watson, we know you’re a facetious little chappy, so what I am telling you is important. I don’t want you to go and do some silly things as soon as you’re finished here because I know what you’re like.

“‘You’ve told somebody here that you intend to go to the gym tomorrow. Don’t you dare. It’s exceptionally dangerous after what you’ve been through.’

“The next day I went to the gym.”

In the years since Russell Watson has rebuilt his life, rebuilt himself. In 2015 he married Louise, who is 20 years his junior, which led to a few snide headlines. “There was some stuff at the start that I was double her age. But not any more. I’d need to be 60 to be double her age.

“We have a good life together. We have a lot of fun. It [the age difference] doesn’t even enter my mind.”

How did the illness change him, I wonder. “I’m much more tolerant of everything now. I wasn’t. I was a s***head, but I let things go now that I wouldn’t have done 10 years ago. Particularly in the music industry. You get an enquiry to do a show and then a week later they don’t want you. Ten years ago I would have taken that incredibly personally. Now it’s, ‘Great. I’ll go and play tennis then.'”

How far has Russell Watson travelled? All the way back to somewhere near the man he wants to be perhaps.

Russell Watson plays the Clyde Auditorium, Glasgow, on May 6. The album True Stories is out now