The advent of conscription in Britain in 1916 was greeted with profound dismay by many in the Liberal party. At Westminster, however, a significant minority of Liberal MPs, who were members of the Liberal War Committee (LWC), were amongst the most enthusiastic advocates of compulsory service, from a surprisingly early stage in the war. It has usually been assumed that those Liberals who embraced conscription were effectively abandoning their progressive principles, and moving to another, more reactionary, political allegiance. This article argues that this was not the case. The Liberal advocates of conscription represented a range of political opinions, but all insisted that they remained Liberals, and many went to considerable lengths to reconcile their support for universal military service with their continued adherence to the Liberal creed. This article reassesses the phenomenon of Liberal support for compulsory service, examining the arguments, activities, and personnel of the LWC. It sheds new light on the vitality of Liberal principles in wartime, demonstrating that Liberal doctrine was often far more flexible than scholars have realized.