During World War 2, a new centralised state-run 'Emergency Medical Service' (EMS) employed doctors and nurses to care for those injured by enemy action and arrange for their treatment in whichever hospital was available. The existence of the EMS made hospitals dependent on the Government, and there was a recognition that many would be in financial trouble once peace arrived.

In 9 October 1941, the Minister of Health Ernest Brown announced that the Government proposed to ensure that there was a comprehensive hospital service available to everyone in need of it.

In 1944 Health Minister Henry Willink prepared a white paper endorsing a National Health Service. The basic principles were; services were provided free at the point of use, services were financed from central taxation, and everyone was eligible for care (even people temporarily resident or visiting the country).

The Labour Government elected in 1945 made manifesto commitments to implement this. In 1946, The National Health Service Act was passed.