Cartwright, whose plays include The Rise and Fall of Little Voice and Road, holds three drama classes every Sunday. He started the classes in 2015 after reading comments from Dame who said she would not be able to afford to become an actress if she was starting out again."It made me really cross because I'm from a working class background," he says.
Reading articles about shrinking opportunities made him "like a bull with a sore head", he says. So his wife told him: "Don't get angry. Do something." He took her advice and set up the drama studio with the aim of bringing through more working class talent, advertising his services in his local fish and chip shop."I got a little card saying 'drama studio' and stuck it on a chippy wall. And I waited. And they came, and they came, and they keep coming."
Two years later, he has five classes in the two locations and has set up a talent agency to represent the budding stars. There is also a youth group. The adult class members range from people who have never set foot on stage to jobbing actors who are honing their skills. There are students, retired people, a few teachers, a former policeman, a fireplace salesman.
Cartwright's efforts come as privately educated actors like Eddie Redmayne, Benedict Cumberbatch, Tom Hiddleston and Damian Lewis seem to have taken over the TV, film and theatre landscape. Last year, The Sutton Trust found that 42% of the winners in three main Bafta award categories had gone to people from private schools, while Sky News recently calculated that 45% of the BBC’s best-paid stars were also privately educated. Also in 2016, researchers found that 16% of actors came from working class backgrounds - half the level of the population as a whole - and that the British acting profession was "heavily skewed towards the privileged."
Cartwright has turned drama teacher after more than 30 years as one of the most vital voices in British theatre. His debut play Road is currently back at the Royal Court in London, where it launched his career in 1986. He has also acted in TV shows like The Village, From Darkness and Coronation Street. With the Cartwright Drama Studio, he hopes to replicate the "explosion of energy and talent" that came with the Kitchen Sink movement of the 1950s. That was fading by the 1980s, he says, when he noticed "the floppy fringe coming back".
His students come from all sections of society. Some would identify as working class, some wouldn't. But he believes the mindset is what sets his studio apart. Cartwright brings casting directors and agents to see his students perform at regular showcases. Some have won small film and TV roles and are working on their own theatre shows and short films. There are no stars yet - but he is sure some have the talent to go all the way.
At the age of 19, Emma Heyes has studied acting at college and is attending the classes in preparation for auditioning for drama school. In the meantime, she's working on the checkouts at Tesco. She has already had enough acting experience to know her accent puts her at a disadvantage.
As part of the training, Cartwright tasks the group members with writing and performing monologues. He recommends one by 38-year-old Scott Brerton. Brerton reads it and it is a bittersweet tale of trying to remember what happened on a big night out. It is exactly the sharp, funny, full-of-life voice that Cartwright is trying to encourage. Brerton had not acted before he started coming to the classes six months ago. He has now been for his first audition and won his first role, performing in a three-night play in Liverpool last month.
It is early days for all concerned, and the "quiet revolution" may end with a whimper or a roar. But at any rate, Cartwright is on a mission to make it happen.