Long before the start of the Second World War, in 1935, the British prime minister, Stanley Baldwin, published a report called Air Raid Precautions In this report he said that local authorities should make plans to protect their people in event of a war. Some towns responded by building public air raid shelters. These shelters were built of brick with roofs of reinforced concrete. However, some local authorities ignored the report so in 1937 the government decided to create an Air Raid Wardens' Service which recruited around 200,000 volunteers.

People in London also used tube stations during the Blitz. They would buy a platform tickets and camp on the platforms for the night. Sheltering in the tube was popular because it was dry, warm and quiet down there. The government was afraid that the overcrowded platforms would disrupt the movement of troops and tried to stop the public from using the tube stations as shelters. The people refused to give them up and the government was forced to back down. In some cases underground stations were closed down and given over to the public to use during air raids.

The tube stations were not as safe as people thought. High explosive bombs dropped by the Luftwaffe could penetrate up to fifty feet through solid ground. On 17th September 1940, a bomb killed twenty people sheltering in Marble Arch station. The worst incident took place at Balham in October 1940 when 600 people were killed or injured. The following year 111 people were killed while sheltering at the Bank underground station. One night 178 people suffocated at Bethnal Green station after a panic stampede.

A census held in November 1940 discovered that the majority of people in London did not use specially created shelters. The survey revealed that of those interviewed, 27 % used domestic shelters (i.e. Anderson Shelters), 9 % slept in public shelters (specially built by the local authorities) and 4 % used underground railway stations. The rest of those interviewed were either on duty at night or slept in their own homes.

Because many people preferred to stay in their own homes during the bombing raids the government decided to look for a way of protecting people in their own homes. So in March 1941 the government began issuing Morrison Shelters.