In May 1940, when France had fallen and things were starting to look serious, Parliament passed laws (an amendment to Defence Regulation 18b) enabling the Home Secretary to detain without trial anyone who might endanger the safety of the realm. Mosley and eight other leading fascists were arrested on May 23rd and another 1600 or so followed in succeeding weeks. Home Secretary Anderson dissolved the BU on May 30th. Around three quarters of the detainees were BU members, representing more or less the entire active strength of the party. The best known non-BU detainee was Captain Maule Ramsay, a Scottish Tory MP who had been embroiled in a spy scandal and who was an overt Hitler sympathiser.