In the run-up to the 2005 election, those advising Tony Blair had a slogan by which they tested manifesto ideas for public service reform: “Further, faster, bigger, madder.”

It was a joke. But more than a joke. It reflected the prime minister’s later remark that – when he looked back on the changes Labour had made in health, education, offender management, welfare-to-work – he wished he had gone “further and faster”.