The heartbreaking stories of Billy Caldwell and Alfie Dingley highlight the ridiculous and cruel situation that parents of children with severe epilepsy are put in by the UK’s outmoded policy on cannabis medicines. Parents of both boys say cannabis oil is crucial to controlling fits but have faced official prohibition, including confiscation. Only now are government ministers talking about a rethink.

This is a long-running injustice. Cannabis was a medicine in the UK until 1971 when it was made illegal by the Misuse of Drugs …