The Sonisphere Knebworth festival is the only date scheduled for a Queen performance featuring Lambert.

CNN: Sonisphere cancellation nixes Adam Lambert and Queen Gig

Other Sonisphere festivals, including events in Poland, Spain and Swizterland, will go on as planned with Metallica as a headliner.

CNN: Sonisphere cancellation nixes Adam Lambert and Queen Gig

"It is with very heavy hearts and much regret that we announce the cancellation of Sonisphere Knebworth 2012, " reads a statement on the festival's website.

CNN: Sonisphere cancellation nixes Adam Lambert and Queen Gig

Unfortunately circumstances have dictated that we would be unable to run the festival to a standard that both the artists and that Sonisphere's audience would rightly expect.

CNN: Sonisphere cancellation nixes Adam Lambert and Queen Gig