Last Wednesday the UK government published a policy document committing itself to independent scientific advice in all departments, with an introduction by the prime minister proclaiming the “international respect” earned by the UK for “its thorough and professional approach to the use of evidence”. Two days later Alan Johnson, home secretary, put that respect in jeopardy with an act of political clumsiness.

He sacked Professor David Nutt, a renowned neuropharmacologist, as chairman of the government’s Advisory Council on the Misuse of Drugs for insisting publicly that last year’s upgrade of cannabis to a Class B drug was not justified by the evidence. Two members of the council quit immediately in protest, more are threatening to follow – and the great and good of British science have lined up to attack the home secretary.