A major academic study released to the Observer this weekend reveals the extent to which actors from relatively wealthy backgrounds are dominating the theatre and film industry.

Following the findings of the Sutton Trust last week, which reported that a privately educated elite enjoyed a hugely disproportionate presence in British professions, the research describes the acting industry as “heavily skewed towards the privileged”. The authors scrutinised a large database of British actors to reveal there are now relatively few working-class actors compared to the population as a whole, and that they earn less than their middle-class equivalents because of a “class ceiling”.

Academics from the London School of Economics and Goldsmiths University of London analysed 402 written survey responses from actors and conducted around 50 interviews. Their results paint a disturbing picture of imbalance, and even prejudice, in show business.

In recent months actors such as Ian McKellen, Julie Walters, Christopher Eccleston and David Morrissey, along with playwright Roy Williams, have joined others in the entertainment world to denounce a new economic shift they believe excludes many would-be actors from breaking into the profession.

Without the support of middle-class or wealthy parents, they complain, actors have little chance of surviving in an industry where access to London’s West End and attending the right social events can be crucial. The high cost of attending drama school and the dwindling of local repertory theatres also means that fledgling actors cannot learn their craft in the provinces.

Oscar winner Eddie Redmayne was educated at Eton. Photograph: Anthony Harvey/Getty Images

The survey, to be published in full in the journal Sociology, found that a huge 73% of actors who replied were from backgrounds that qualify sociologically as “middle-class”, despite the fact this sector makes up only around 29% of the whole population. This suggests that the fears of stars such as Walters – who has warned that “the way things are now there aren’t going to be any working-class actors” – may be well-founded.

Last week the Sutton Trust published research showing that 42% of British Bafta winners went to a fee-paying school. This statistic came in the wake of Williams’s comments at an arts panel held in Northampton this month, when the award-winning black playwright said the situation for working-class actors was getting “worse and worse”. He accused the profession of being dominated by actors from wealthier backgrounds, such as Eton alumni Damian Lewis, Tom Hiddleston, Eddie Redmayne and Dominic West.

In analysing data drawn from the Great British Class Survey, a huge social study compiled over two years, the researchers – Dr Sam Friedman, Dr David O’Brien and Dr Daniel Laurison – found that only 27% of the actors who responded were working-class, with parents who did “intermediate, routine or semi-routine work”. Actors from the middle classes also reported average household earnings of £46,100 a year, while less well-heeled actors had an income of £28,700.

One anonymous actor whose parents are doctors told researchers “his existence as an actor is heavily contingent on the ability to ‘call mum’ during lean spells for financial top-ups”. “It’s not great,” he said, “but I can’t imagine how I would be able to do it if it wasn’t for her.” Another actor from a very wealthy background said this support, and the fact he had attended an elite public school, gave him a big advantage. “I have an apartment in central London, I have another that pays rent, I have money, assets, capital. It’s desperately unfair. My friend lives in a Peabody house and struggles to find all kinds of work. He has a degree from Cambridge but he sells maps and chewing gum and washes cars. If I go off and have a successful career now, it’s unfair – really unfair.”

By contrast, a black British actor told researchers that with financial security he would be able to take risks: “I would have been able to see more theatre and meet people.”

The academics also found that getting into the right drama school was harder for working-class people. “Fifteen interviewees from professional or managerial backgrounds had either attended leading London drama schools or Oxbridge, compared to only five working-class actors.”

At auditions some actors said a working-class accent weighed against them: “One of my lecturers said to me: ‘Have you ever considered going back and being a plumber?’ You look back on it, it’s like an assault from various angles.” Others felt that working-class actors were offered limited roles. “I’ve played more nurses than there are in the whole of St George’s Hospital,” complained one black character actress in her 40s. “I started to get bored of that, and I wouldn’t take [the role] if all she was saying was ‘the doctor will see you in a few minutes’.”

Writing in Sociology, the researchers said they had unearthed “not only the striking under-representation of actors from working class backgrounds” but that, even when taking into account variables such as schooling, education, location and age, “working-class actors have lower incomes”.