An app to schedule meetings between the defence and prosecutors so that cases can either be resolved quickly or proceed to trial has been described as “entirely unreliable”.

The Crown Office app arranges newly introduced Pre-intermediate Diet Meetings (PIDMS) but lawyers have said it runs poorly and is unnecessarily complicated.

Julia McPartlin, president of the Scottish Solicitors Bar Association (SSBA), said: “The Crown Office had to create the app at quite short notice so there are lots of problems with it, and I think it’s fair to say that they acknowledge that there are.

“The main problem is that it uses a two-factor authentication process, so you have to have your mobile next to you to get the code to log on, so you cannot delegate the booking to admin staff.

“Then, once you get in it, despite having gone through that authentication, you still have to fill in all of your details again and – I’m not sure why – if you don’t do it quickly enough it empties all of the fields and you’ve got to do it again.

“The upshot of that is that a lot of people are not using the app, and instead they are contacting the PF deputes directly.

“We’re not supposed to do that and we’ve been told that from June they will insist that we use the app which is not ideal.”

She added: “It’s overly complicated, with the authentication and the details you have to put in. There’s no confidential information going in, it’s just a reference number, so I don’t really understand why it has to be so complex.”

A Crown Office spokesman said: “The PIDM initiative has proven successful in ensuring summary criminal cases are dealt with more effectively and efficiently.

“COPFS will continue to work closely with justice partners to respond to the challenges the sector has faced and promote good communication with the wider legal profession to make improvements that will not only benefit the justice system now, as it recovers from the effects of the pandemic, but in years to come.”