Sir Alan Ayckbourn today launched an attack on the Hollywood invasion of the British stage.
The leading playwright said producers who turned to film and television stars to attract audiences would ultimately damage the West End because they would get increasingly disappointed with poor performances.
He said most film stars were incapable of acting on stage and could "barely be heard beyond row three".
He added: "The theatre is being stuffed with the stars' fans. What they experience is a poor performance and they go out profoundly disappointed and disenchanted. That is another blow for the theatre. You've emptied the theatre for a whole load of people who will never go again."
Sir Alan, whose plays are performed more than any other living British writer, also ridiculed the inability of the worst offenders even to know what to do with their arms while treading the boards.
He said good British actors were often overlooked in preference for big names. "We have tremendous talent in this country.
"Young actors have never been better, but they are fed up with seeing their jobs whipped away by people who have chanced by a TV camera or stood in a field taking off their clothes."
In 2002, Sir Alan, 67, gave a damning review of Madonna's performance in Up For Grabs. He said: "You might as well have put her on stage eating a plate of spaghetti and put a rope round her chair instead of putting her in a theatre where she wasn't at home and was struggling."
Sir Peter Hall, who has directed a number of US stars, said greater emphasis was being put on the actors than the play they were in.
Matt Damon, David Schwimmer, Matthew Perry and Glenn Close have all had lukewarm reviews in London.
