British actor Patrick Stewart is urging more Hollywood stars to appear in stage productions in London's West End, because they draw more crowds to theatres.

Despite Rob Lowe, Val Kilmer, Woody Harrelson and Kim Cattrall being listed among the Hollywood stars who have recently appeared on stage in London, X-MEN star Stewart, 65, believes British actor's union Equity is blocking US stars from making their way to the UK.

He says, "I wish more Americans would come back to the West End, and bring new Hollywood stars with them. They inspire a whole new range of people to come to the theatre who wouldn't be there otherwise.

"The problem is the unions; they get in the way and don't help the actors with visas. It's outrageous."

But Equity spokesman Martin Brown has hit back at Stewart's claims, explaining, "Patrick has misunderstood. If an actor has international status, they get a work permit and everyone is happy.

"We also have an exchange agreement with American Equity on a job-for-job basis so lesser names can come over here and vice versa."