There are "many instances" of crucial Government decisions made over WhatsApp and other messaging services being unlawfully deleted, the High Court has heard.
Campaign groups All the Citizens (ATC) and the Good Law Project (GLP) say ministers are breaking the law by deleting messages and using private accounts for Government business.
Even Boris Johnson has used personal WhatsApp accounts to communicate “critical decisions”, the High Court heard yesterday (TUE).
But Government lawyers argued ministers and officials used instant messaging apps because they need to communicate quickly with each other in the wake of the pandemic.
Ben Jaffey QC, representing ATC, said the messages could serve as a "public record for future societies”.
And he said deleting them would prevent “scrutiny through inquiries or court proceedings”
He said in written evidence: "It is possible to identify many instances where messages concerning government business which were sent/received using personal devices or accounts were never copied or transferred to any government system for archiving or records purposes, or were only copied/transferred when there was a need to retrieve the message for some particular purpose."
The court heard a Cabinet Office policy requiring messages be automatically deleted conflicts with the Public Records Act 1958.

From November 2020, Mr Johnson was being sent "confidential information" via WhatsApp to his personal device, court documents argue.
It was also said messages which were later screenshotted and published by the Prime Minister's former chief adviser Dominic Cummings were never being recorded on Government systems.
A witness statement from Sarah Harrison, chief operating officer for the Cabinet Office, says private devices are used by Government officials on a "daily basis".
Another witness statement from William Vineall, of the Department of Health and Social Care, said the Prime Minister, former health secretary Matt Hancock and other senior officials used personal WhatsApp accounts and email to discuss major government business, including the response to the Covid pandemic.
Another said Education Secretary Nadhim Zahawi has previously used automatic deletion WhatsApp on his personal phone for government communication.
Mr Jaffey went on to say that at least one of the six top civil servants had used an automatic deletion function.
He also argued the actions of ministers and civil servants did not comply with their own policies.
He said: "The concern is the material is not being properly considered and is at risk of being deleted and lost entirely, and therefore meets the test of falling foul of their own policies."
He added: "The public has the right to see historically important public records, many of which centre around important policy relating to the pandemic.
"We say that these messages should have been archived and kept for future reference."