Crown Office and Scottish Courts and Tribunals Service staff told a survey that they are “drowning in emails” as they attempt to deal with technology that in some cases is more than two decades old.

Research by Unity Consulting on behalf of the Public and Commercial Services Union (PCS) also found that employees were regularly working unpaid through weekends to deal with the backlog.

The research involved interviews with a small number of employees which were then used for a survey answered by 376 people at the Crown Office and 237 at SCTS.

At the Crown Office, 76 per cent said they had experienced or seen mistakes made because of pressure on staff. At SCTS, 30 per cent said they themselves had experienced errors, while 26 per cent said they had witnessed them.

One member of staff at the Crown Office said: “Cases are being flung out of the door due to managing our caseloads. We are expected to also juggle post-indictment work including working along with [advocate deputes] which takes away a lot of time for reporting cases.”

Another said: “I myself have made mistakes in terms of not following up on tasks because we are constantly overwhelmed with work and expected to juggle multiple urgent issues, many of which are often not urgent but you are made to do them urgently.”

Ruby Gibson, PCS national officer for Scotland, said: “This is an outrageous situation, and the responsibility lies at the door of the Scottish government and senior management in COPFS and SCTS. We cannot have a Scottish justice system that runs off unpaid labour and the goodwill of staff. The workforce deserves better. The Scottish public deserves better.”

A spokesman for the Crown Office said: “COPFS values its employees very highly and their welfare is of great importance to the organisation. We will consider this report and discuss with PCS.”

A spokesperson for Scottish Courts and Tribunals Service said: “We have just received the PCS Scotland report and will take the necessary time to review its findings. We are committed to continuing our partnership with PCS to achieve the best outcomes for those we serve. The SCTS is dedicated to adapting to the evolving needs of the justice system, with staff wellbeing being of paramount importance.”