A root-and-branch shake-up of the way sensitive information is handled across Whitehall has been ordered, which will see data handling systems subjected to regular independent assessments and spot-checks by the data watchdog.

Other measures detailed on Wednesday by Sir Gus O’Donnell, the cabinet secretary, include compulsory training in data handling for government employees and an increased use of encryption. In announcing the overhaul, the country’s most senior civil servant admitted that ministers and officials had to win the trust of citizens and businesses in their ability to handle information.