The former Dr. Feelgood star, who was given the all-clear in his cancer battle last year (14), was performing at the Wickham Festival in England when he was taken ill and left the stage 30 minutes before the end of his set.

No more details about his condition have been given, but festival organisers have since tweeted fans to reassure them, writing, "Wilko Johnson is OK and has thanked the fans for their support and concern after feeling ill on stage."

The message was later retweeted on the star's own page.

Johnson was diagnosed with terminal pancreatic cancer in early 2013 and decided to go without treatment in favour of playing a farewell tour.

However, in April, 2014, he underwent a dramatic operation to save his life by removing several organs and part of his stomach, and he later confirmed he had been given the all-clear from cancer.