From Benedict Cumberbatch to Tom Hiddleston and Eddie Redmayne - in the last few years, some of Britain's biggest acting stars have been those who went to public schools. That's led to concerns about the prospects for working class actors. Dramatist Jim Cartwright has been telling BBC arts reporter Ian Youngs how he started his own drama studio in Lancashire to bring through working class talent. (Image: Jim Cartwright drama studio. Credit: BBC)