Charities are hiring staff with “privilege rather than potential”, according to the author of a report highlighting the stark class divide in the sector.

Working-class people are less likely to be hired by charities than by employers in the public and private sectors, said the EY Foundation, which supports young people from low-income backgrounds to progress in professional roles.

Working-class people also find it harder to climb the career ladder inside charitable organisations, with the report highlighting how charity chief executives are twice as likely as the wider population to have gone to private school, rising to three times as likely for the biggest charities.

Duncan Exley, the author of the report, said charities were missing out when teams hired within their own social circles and class bubbles, which the research showed tended to skew towards the most affluent third of people.

He said: “You’re cutting off an awful lot of talent, you’re going to recruit people who have privilege rather than people who are potential.”

One issue identified was that most charities were not even tracking their own progress on how many working-class employees they had and which roles they held.

Of the 100 charities studied in one piece of independent research that went into the report, only one reported on the social class of its staff members. None in the main sample of 100 foundations reported on the social class of its board.

Exley, who is the author of The End of Aspiration? Social Mobility and Our Children’s Fading Prospects, said there were endless hurdles for working-class people in the sector.

These include a lack of progression from volunteering to a salaried job, having nobody to advocate professionally for them, and a lack of access to London where most large charities are based. Furthermore, he said it was simply not widely known among working-class young people that it was possible to have a well-paid career in the charity sector.

Even where they were successful in gaining professional jobs, working-class people often had to do a “crash course in applied anthropology” to understand what they needed to do to climb the career ladder, Exley said.

For example, a lot of working-class people thought “the way that you progress is the same as a way that you become a fairytale princess – that you’re good and virtuous and keep your head down and someone will notice you and want to reward you”.

“And then they were passed over for promotions,” he added. “The way you progress is you get close to the right people or you get close to the right projects, and in working-class professions that’s seen as being quite sneaky and arse-licking the boss and that sort of stuff.”

Part of a lack of action among charities was due to a “discomfort” about talking about class, the organisations said in one study that went into the report.

However, it also noted many charities wanted to improve their class diversity but lacked the resources or knowhow to do so. A small minority had programmes to actively recruit more working-class people.

Exley said charities could not afford to “sit on their laurels” and expect talented working-class people with strong values to fight to work for a charity when there were now so many social enterprises or businesses with a social mission.

“I think there’s a real danger of complacency there and potential good employees who want to make a positive difference in the world looking somewhere else,” he said. “A lot of charities are about opportunity and a lot of opportunities aren’t there.”