In August 1939 Adolf Hitler had long been making speeches suggesting he was going to send the German Army into Poland. The British government began to prepare for war with Nazi Germany, and Neville Chamberlain asked Parliament to approve the Emergency Powers (Defence Act). Passed on 24th August, it empowered the government to take measures to secure public safety, the defence of the realm and the maintenance of the public order.
Over the next five days around 100 new measures were taken. This included the calling up all military reservists and Air Raid Precautions (ARP) volunteers to be mobilized. About half a million people enrolled in the ARP and others enlisted in the Territorial Army or the RAF Volunteer Reserve.
On 27th April 1939, Parliament had already passed the Military Training Act. This introduced conscription for men aged 20 and 21, who were now required to undertake six months' full-time military training.
Parliament also passed legislation that protected some important occupations from national service. After consulting with business leaders, the government published the Schedule of Reserved Occupations. Employers were also able to ask for individual key workers employed in one of these occupations not to be conscripted into the armed forces. By the end of 1940 more than 200,000 men had been granted deferment at their employers' request.
On the outbreak of the Second World War, Parliament passed the National Service (Armed Forces) Act, under which all men between 18 and 41 were made liable for conscription. The registration of all men in each age group in turn began on 21st October for those aged 20 to 23. By May 1940, registration had extended only as far as men aged 27 and did not reach those aged 40 until June 1941.
Provision was made in the legislation for people to object to military service on moral grounds. Of the first batch of men aged 20 to 23, an estimated 22 in every 1000 objected and went before local conscientious objection tribunals. The tribunals varied greatly in their attitudes towards conscientious objection to military service, and the proportions of conscientious applications totally rejected ranged from 6 per cent to 41 per cent.
The political and moral views of the tribunal chairman were vitally important. It was difficult always to get a fair hearing in London, especially during the Blitz. On one occasion the chairman told the applicant that his request was rejected because "Even God is not a pacifist, for he kills us all in the end".
On 18th December 1941, the National Service Act was passed by Parliament. This legislation called up unmarried women aged between twenty and thirty. Later, married women were made liable to be directed into war-related civilian work, although pregnant women and mothers with young children were completely exempt.
By the end of 1939 over one and a half million men had been recruited into the armed forces. Of these, 1,128,000 joined the British Army and the remainder were equally divided between the Royal Navy and the Royal Air Force.