Actor Kevin Spacey called out an audience member in the middle of his play Clarence Darrow after a ringing cell phone interrupted a powerful monologue.

The House of Cards star is in the midst of a two-and-a-half week run at The Old Vic theatre in London, and on Wednesday (04Jun14), Spacey's improvisation skills were put to the test when a ring tone interrupted him during a passionate scene.

The audience member attempted to ignore the call, prompting Spacey, who remained in character, to blurt out, "If you don't answer that, I will!"

His speedy response sparked a round of applause from the crowd.

The production marks the third time Spacey has played the lawyer and civil rights hero. He took on the one-man play in celebration of his decade-long stint as the artistic director of The Old Vic.

The actor will step down from the position next autumn (15) and will be replaced by director Matthew Warchus.