The Telegraph reported that prime minister David Cameron was growing increasingly impatient with "institutional failures and his ministers have complained privately about regularly receiving 'useless' advice from below-par officials."

The newspaper also cited claims by Cameron's former adviser Steve Hilton that the civil service "could function effectively with a 90 per cent cut in staff."

Prospect Deputy General Secretary Dai Hudd said the idea of identifying and firing civil servants by ranking all government officials by ability was wrong. "This would be a cruel policy and legally challengeable," he said.

"It would set colleague against colleague and destroy collaborative working – worsening morale rather than improving performance, and creating a culture of back stabbing, uncertainty and fear. It would increase stress and adds insult to the injury of job cuts, pay freezes and attacks on pensions."

Hudd pointed out that even Cabinet Office minister Francis Maude had distanced himself from the newspaper's rhetoric, by admitting that effective procedures already exist in the civil service for dismissal on grounds of performance.

"Blaming hard-working public servants and making ill-thought through comments will not in any way contribute to making the civil service a more efficient and effective organisation," said Hudd.

"Comments like this are just another way of trying to push the blame for the government's own errors – typified by yesterday's u-turn over the F35 jet fighter – on to individuals."

Hudd added: "Ministers' time would be better spent focusing on what civil servants can do to deal with the impact of the 80,000 job losses already under way. This nonsense from Cameron's outgoing policy adviser Steve Hilton will not result in any increase in focus or improvements in performance."

The unwarranted government attacks on civil servants' pay, pensions, jobs and now their performance will feature strongly in debates at Prospect's biennial national conference in Bournemouth, starting on May 22-24.