I recently posted an identification card for an Invasion Defence Organisation member in London. I was recently sent this Stationery Office booklet "Consolidated Instructions to Invasion Committees, 1942".
It would appear that terminology varied between areas - some use Invasion Committee and others Defence Committee - but it appears they provided a similar response to an area being invaded. Primarily to maintain a semblance of order in the area, ensure the roads were kept clear of refugees, assist the military where necessary and ensure the local populace were informed about water, food and cooking facilities in the event the electricity and gas were cut off.
All the Civil Defence Services were brought together along with police, Home Guard, local councillors and volunteer groups such as the WVS. All of these would have responsibility in ensuring the public were informed about what they should do.
Courtesy of George Pagliero.
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