Roberto Alagna will sue opera house La Scala if they do not let him return to the stage following his abrupt exit during the second performance of Zefferelli's Aida.

The opera singer walked off after booing began, forcing understudy Antonello Palombi to come on in jeans and without a vocal warm-up to continue. His contract with the opera house has now been annulled.

Alagna told Reuters: "I went there to sing, to give the audience joy and pleasure. But what was I supposed to do when some people started booing? What if they had thrown stones at me or some crazy person had attacked me? La Scala should have protected me, the show should have been suspended."

La Scala spokesman Carlo Maria Cella explained: "His behaviour has created a rift between the artist and the audience, and there is no possibility of repairing this relationship. He did not leave because he was sick; he left voluntarily."