The Chief Medical Officer apology for the distress caused after he sent warning letters to 4800 GPs over their opioid prescribing has been dismissed as an “academic justification for a rubbish project with junk methodology and junk outputs”.

The ­original letters, signed by Professor Brendan Murphy, targeted doctors deemed to be among the top 20% of opioid prescribers, warning that some could face investigation from the Department of Health’s practitioner review program.