The CPS watchdog has told the service to “act urgently to get a grip of this situation” as it revealed that letters are full of misspellings or are missing crucial information regarding delays.

The report reveals that since the last check, in 2018, the “quality of letters has deteriorated”. A scrutiny of 351 CPS letters, where two-thirds were sent to crime victims, found only 66 were “good quality”. Around 32 per cent were just “adequate”, and 49 per fell below the required standard.

While the 2018 inspection showed nearly 75 per cent of letters were inadequate, there was a slight rise in acceptable letters. However, the share of commendable letters dropped from 25.7 per cent to 18.8 per cent. HMCPSI’s chief inspector, Andrew Cayley KC, observed there was “insufficient overall progress”.

Mr Cayley said: “Many written responses go to victims of crime, and the fact they are still receiving formulaic letters, or where basic details are wrong, is disappointing. The CPS must act urgently to get a grip of this situation. This is not a case of us singling out letters which had simple spelling mistakes – there were real inadequacies, and a review of the system is needed now to restore confidence.”

One significant issue was tardiness, with 32.5 per cent of the letters being dispatched late. Performance varied regionally, with the worst CPS area only responding to 16 per cent of letters promptly.

Furthermore, the CPS was found lacking in keeping complainants in the loop about delays. Out of 116 delayed cases, the CPS failed to dispatch an interim letter in 61 instances. Even though most of these interim letters provided an expected response time, “many failed to give a reason for the delay”.

A CPS spokesperson said: “We are pleased there have been significant improvements since our last inspection in 2018, with empathy, timeliness and our acknowledgment of mistakes all highlighted as strengths. We recognise that there is more that can be done, and we will continue to drive forward improvements so that we can provide the best possible service for victims.”

Andrea Simon, executive director of End Violence Against Women Coalition, said victims too often received CPS letters “containing generic and vague ‘cut and paste’ [text] from templates, having a general lack of compassion towards the recipient”.

She added: “It is highly concerning that such poor progress has been made […] and that there are still significant failures to notify victims about delays to their cases or signpost them to help and support.”