Wilko Johnson shouldn’t really be here. Five years ago, after falling ill between shows, he was diagnosed with cancer. It was serious, he was told. As bad as it could possibly be: terminal.

Wilko, frontman with 70s pub-rock band Dr Feelgood isn’t the sort of bloke to sit around feeling sorry for himself though, and hastily arranged a farewell tour. Far from being sombre, the shows were a celebration of a life spent in rock from one of the most dynamic men in the business.

One of those dates was in Oxfordshire – at Cornbury Music Festival. It was a hot day and the crowd was huge – many people turning out just to see this iconic Canvey Island guitarist, whose tumultuous musical career was charted in the award-winning Julien Temple film Oil City Confidential.

It was a scorching set. And when he said goodbye for the final time, there was scarcely a dry eye on the field.

Three years later he was back – leaping around the stage and strutting his trademark duck walk as he thrashed out a searing set of choppy rock & roll; tunes so punchy that, back in the 70s, they kickstarted punk rock.

So what happened? “Cornbury saved my life!” says Wilko, at home in the Essex resort of Southend.  “That day was a bit of a turning point because it allowed me to meet someone who helped me survive cancer. So it was quite an event.”

That person was fan, gig photographer and, crucially, surgeon, Charlie Chan. Charlie had photographed Wilko previously and had been puzzled as to why, given the extent of the star’s supposedly inoperable pancreatic cancer, he was not only alive but in relatively good shape. He collared Wilko after the show and put him in touch with a colleague at Addenbrooke’s Hospital in Cambridge.  “Charlie turned out to be a cancer specialist and took an interest in my case,” Wilko recalls. “He’s a very inquisitive character and came to my house to talk about it. It was off the reel!

“They had told me three times at hospital that I was going to die and there was nothing I could do about it.

 “But when I went to Addenbrooke’s, the people were so clever. And it saved my life.”

They removed a tumour weighing 3.25kg.  “It was the size of a melon,” he says. “I had looked pregnant carrying that thing around. On stage my guitar would rock on it. I could never ignore it.”

His recovery was the perfect way to round-off a farewell tour.

“The whole year was full of really great experiences and so many fantastic things happened,” he says. “I played in Japan where half knew what I was expecting.It was emotional, just how great rock & roll should be: in the moment. It’s got nothing to do with the past or future but is in the moment. And if you think you’re going to die, you feel in the moment – and that’s great for rock & roll.”

Wilko may look like a bruiser but he’s a cultured soul. A poet and writer he studied Anglo-Saxon and ancient Icelandic sagas as part of a degree in English Language and Literature, travelled overland to India and, on his return, became a teacher. But it was always music which absorbed him.

“Just call me Oscar Wilde,” he laughs. “But music can absorb all kind of things. Other times it’s just ‘1234!’ “It’s a kick.”

His first band Pigboy Charlie grew into Dr Feelgood, alongside frontman Lee Brilleaux, bassist John B ‘Sparko’ Sparks and John ‘The Big Figure’ Martin.

Hits included Roxette, Back in the Night and She Does It Right. Unfortunately, the band were as punchy off stage as on, and Wilko and Lee clashed – so much so that he left in 1977 – before the band’s biggest single, the Top 10 hit Milk and Alcohol.

Wilko went on to play with Ian Dury and the Blockheads while Feelgood carried on without him. Lee died in 1994 of lymphoma. Wilko carried on rocking.

“All my life I’ve never planned things,” he says. “I let things happen – and rock & roll is my life. If you’d told me when I was 21 that I’d still be playing rock & roll on my 70th birthday, I wouldn’t have believed you. I never thought that. I have just made a living drifting around, playing clubs in London, Paris and Tokyo. And then Julien Temple came along.”

Temple’s Oil City Confidential was instrumental in exposing Wilko to a new audience.

“It was great,” he says. “I think it reminded a lot of people what had gone down before and turned a new generation on. I just noticed more and more people coming along to gigs.”

It was set among the mud banks, bleak caravan parks and petrochemical facilities of his native patch of the Thames estuary – the place which, given its rich blues rock scene, he describes as the Thames Delta.

“We lived out in the estuary but had to play in London,” he says. “In the early days we didn’t have a lot of gigs, so we’d just sit here making up fantasies, like living out in the Thames Delta.”

The same stretch of coast gave birth to Eddie and the Hot Rods, Procol Harum, The Hamsters and, more recently, Nothing But Thieves, The Horrors and, err... Busted. I suggest there must be something in the water.

“There’s definitely something in the water,” he laughs. “But I don’t know if it makes for good music.”

Despite their messy break-up, he is proud of what Dr Feelgood achieved. “Let’s face it, we were the best exponent of that sound,” he says. “Dr Feelgood was right on the brink of making it big and we started to tour America but then argued and broke up. It’s typical of my life. But I joined another band and carried on.”

 And he misses his one time adversary. “I didn’t have anything to do with Lee,” he says sadly. “We never really met again. When he fell ill, and people told me it was serious, my brother went to visit him. I didn’t know if he wanted to see me though as it had been 20 years. He said he did though, so I prepared to go, but before I got to see him, he died.

“It’s a bit sad, but c’est la vie.

“He was fantastic and Dr Feelgood was Lee. It was his nervous, violent energy and I just used to bounce off that. People used to say it was the two of us, but it was Lee – and we were good friends in the early days, and that’s what I look back on.”

He goes on: “Everyone had heard of Dr Feelgood but not everyone knew Wilko Johnson. And when I had to carry on alone it was a bit of a struggle while they had it made!”

Tomorrow he returns to Oxford with a show at the O2 Academy. It finds him in good shape. He also has a new fanbase who know him not from music but from his latest career move as an actor, having played the mute executioner Ser Ilyn Payne, in the first two seasons of Game of Thrones.

“I’d never done any acting before but they asked me to an audition,” he says. “I didn’t even know what Game of Thrones was. But they explained that my character didn’t have a tongue so I didn’t have to learn any lines.

“They just wanted someone who could give people a dirty look. And I can do that!”

  • Wilko Johnson plays the O2 Academy, Cowley Road, Oxford tomorrow (Friday). Go to ticketmaster.co.uk