Simon Case said dealing with the then-prime minister's team during Covid was "like taming wild animals".
From "disappearing messages" to the urge to "let the virus rip", the messages expose the chaos in government during the pandemic.
The privileges committee is grilling the former prime minister over claims he misled MPs.
"Unauthorised disclosure of government information to the media is clearly inappropriate," cabinet secretary Simon Case said.
The prime minister's wife could be summoned to give evidence to MPs over fresh partygate claims.
Unions are threatening industrial action over plans to slash civil service jobs by 91,000.
Those at the top of leading British establishments are not exactly setting a shining example at the moment.
Cabinet Secretary steps back from leading probe after gatherings said to have been held in Simon Case’s own department.
Act now, think later has always been his trademark.