Helena Bonham Carter

Almost 300 famous actors, writers urge Britain to stay in EU

If celebrity power were votes, Britain's European Union membership would be secure.

Almost 300 actors, writers, musicians and other cultural figures appealed Friday for British voters to back the "remain" side in a June 23 EU membership referendum, arguing that a vote to leave the 28-nation bloc will leave the U.K. "an outsider shouting from the wings."

Signatories from the acting world included "Sherlock" star Benedict Cumberbatch, "X-Men" superhero Patrick Stewart, Jude Law, Bill Nighy, Keira Knightley, Kristin Scott Thomas, Chiwetel Ejiofor and Helena Bonham Carter.

They were joined by spy novelist John le Carre, "Wolf...