Minute 1 of the War Cabinet minutes from the meeting held on 8th September 1939:
The Secretary of State for Air informed the War Cabinet that further leaflet dropping operations had taken place over north-west Germany, including Kiel on the night of the 7/8 September. Apart from certain reconnaissances, there had been no other operations worth mentioning.
A discussion took place as to whether the dropping of leaflets should be continued. It was pointed out that there was a strong feeling in some quarters that it was not right that, while Poland was being severely bombed by Germany, our operations should be confined to the dropping of propaganda. On the other hand, there was good reason to believe that the German authorities feared the effect of propaganda, and the fact that aircraft were able to fly with impunity all over the North West of Germany would have a depressing effect on the morale of the German people.
It was generally agreed that the material which should be incorporated in the leaflets was a matter which could best be left to the discretion of the Ministry of information, but that the suggestion that the Prime Minister’s Broadcast to the German people would form a suitable leaflet should be brought to the notice of the ministry.”
The Secretary of State for Air was Sir Kingsley-Wood
Meanwhile over Poland …