The vast majority of charity workers are facing workplace stress, with more than 40 per cent saying their jobs are damaging their mental health, a survey from the union Unite has found.
The survey, to which more than 850 people from 238 charities replied, found that 80 per cent of respondents said they had experienced workplace stress in the past year.
Forty-two per cent of respondents said their jobs were bad for their mental health.
Just over a third of respondents said they did not feel valued at work, and 44 per cent felt they did not work for a well-managed organisation.
Four in 10 felt their jobs were insecure, the survey found.
Twenty-two per cent of respondents either disagreed or strongly disagreed with the statement "I work in a safe and healthy working environment".
Despite this, the vast majority of respondents (92 per cent) said they believed in the work they did in their jobs.
There have been a number of recent examples of stressful workplaces being reported in the charity sector. For example, Amnesty International was the subject of a damning report into its "toxic" workplace culture.
A report last year produced for the RSPCA by the trade union Unite said that three in 10 staff members at the charity had been bullied in the previous 12 months.
Siobhan Endean, national officer for charities and the voluntary sector at Unite, said the survey’s findings were "profoundly disturbing" and many charities were not committed to staff welfare.
She said: "Staff employed by charities and NGOs tend to be very committed to their organisations and are usually loath to speak out because they fear it will damage the causes they work for. However, many workers are clearly at breaking point.
"It is impossible to get away from the stark fact that catastrophic mismanagement of dedicated and passionate workers is making them ill and creating widespread misery.
"Unite is putting employers on notice that management has to change and they need to work with our representatives to tackle these problems , which are at epidemic levels."
Unite has produced a guide to the ways in which trade union representatives can challenge employers on workplace issues that result in mental health problems and stress.