Staff complained of being overworked and understaffed – with some pointing to Brexit as a contributing factor.

Overstretched government departments are reaching breaking point, a civil service union has warned.

Staff complained of being overworked and understaffed, with some pointing to Brexit as a contributing factor.

A survey by the FDA union found more than 80% of top civil servants are having to put in extra unpaid hours – just to get their work finished.

A quarter said they usually give up between six and ten hours of their time every week. And nearly three quarters believe their department is understaffed.

Amy Leversidge, assistant general secretary of the union, told Channel 4 News: “There’s only so many more hours you can work in a day… In a lot of departments, goodwill has been exhausted and they still can’t get everything done.”

She warned: “We will end up at a point where things can’t be done.”

Respondents included senior officials from the Home Office, Foreign Office and the newly-created Brexit Department.

One Home Office employee claimed: “At one point immediately after EU exit I was covering what is now the work of several teams and I was struggling to cope … I began working extremely long hours and became extremely anxious and stressed. In the end I went for counselling.”

Another said they had “never felt so dispirited” after decades of working in the civil service. “Years are being taken off my life and my wellbeing and marriage suffer enormously,” they said.

An HMRC staffer complained: “Due to the pressures caused by Brexit, I have worked up to 60 hours per week over recent months.

“Working these additional hours would be more palatable if civil servants were not still subject to a pay freeze, and if ministers did not insist on criticising the performance of civil servants in the media.”

Around 70% of staff surveyed said that morale was running out in their department and it was having an impact on how effective their department was.

The FDA’s report claims there is a “worrying trend of working excessive hours becoming the ‘new normal’.” And many staff believe this is damaging their health and wellbeing, it said.

“Fundamentally, this cannot continue if the civil service is to deliver on the challenges ahead.”

Amy Leversidge warned: “At the moment, things are being managed by the dedication of civil servants… It’s the saving grace, really – the fact that they are putting in the goodwill. But that only lasts for so long.”

A Cabinet Office spokesperson told Channel 4 News: “Civil Servants work incredibly hard to deliver important public services and projects, including laying the groundwork for the UK’s successful exit from the EU.

“This is recognised by senior leaders, and all staff have access to a range of flexible working arrangements to help them manage their work life balance more effectively.”