Michael Sheen has said the world of film and theatre will suffer from the increasing lack of diversity in performers.
Speaking to an intimate audience at an event in central London on Thursday, he said routes into the industry are being cut off for under privileged actors.
The Special Relationship and Damned United star, 47, worked his way to fame after performing in school plays and at his local youth centre in his home town of Newport in Wales, before being given a special grant to put him through drama school.
But, he said: "That pathway wouldn't be open to me nowadays. That theatre had its funding cut and the school isn't even there anymore.
"How on Earth are we going to get new people from less privileged backgrounds?"
His comments came as he spoke to fans at an inaugural interview looking into the lives and careers of British Independent Film Award (BIFA) nominees.
He told Time Out global film editor Dave Calhoun that he had similar feelings about film "snobbery".
"There is no difference between high art and low art," he said.
"You never know what's going to hook you and worry your unconscious for the rest of your life.
"Our lives are full of fragments of things that we see and keep with us. If you apply a sort of snobbery to what you are going to allow to be meaningful to you, you are shutting down the possibility of having more things that can be important to you."
Now spending most of his time in Los Angeles where he is in a relationship with American comedian Sarah Silverman, the Masters Of Sex creator already has a BIFA under his belt and in 2009 was named GQ Magazine's actor of the year.
Known for his skilled and in-depth portrayals of real figures - including Kenneth Williams, Brian Clough and former prime minister Tony Blair on three occasions - he explained how learning how to play a person with mental health problems was a major turning point in his acting career.
Describing his role as an architect with Tourette's syndrome and obsessive compulsive disorder in Dirty Filthy Love, he said: "It was the first time where I felt a real responsibility over a character. I felt I really had to get it right."
The challenge, he said, was strongly influenced by watching the 1989 documentary John's Not Mad as a teenager and realising that his school friends found the man with mental health issues "hilarious".
"Later on," he said, "John, who the film was about, saw Dirty Filthy Love and got in touch. It was a pivotal thing for me."
Michael added that the key to playing real people well is to combine deep research and spontaneity so "the audience is comfortable with me playing that character so I can take them on the story without them thinking about how like that person I actually am".
"Really good acting is about a balance between control and loss of control."
But he also said that one of his favourite roles was playing the chilling fictional vampire lord Aro in the Twilight Saga films - a character he built from combining Laurence Olivier's Richard III, the child catcher from Chitty Chitty Bang Bang and the fairy tale big bad wolf.
After taking his young daughter to see the premiere of Breaking Dawn 2, he said: "Part of why I got into the movies was because she was so into the books.
"She was sitting next to me in the cinema and when I did that (manic laugh) she grabbed my thigh and gasped and I thought 'Yes! I got it!'
"Taking your place in the pantheon of vampires in film is a real honour."