GUITAR legend Wilko Johnson is a surprise addition to this summer’s Sonisphere festival, in Knebworth, Hertfordshire.

The former Dr Feelgood star, will be performing on the same bill as Metallica, Iron Maiden and Slayer as part of a celebration of 40 years of festivals.

It marks a further extension to the career of Wilko, who lives in Westcliff, and announced his retirement last year after being diagnosed with terminal cancer.

He then announced he would continue to perform as long as his health allowed.