You are waiting for an answer on a wrong question that is based on the unproved claim that the mission of FC was to protect London,which was a military target where were living a lot of civilians .
The main mission of Dowding was NOT to protect London,but to conserve FC intact so that it could be used when its intervention was needed = on the start day of Sea Lion .
Your major political blow is an invention : there was no major political blow when Coventry or Liverpool were attacked or when London suffered very big during the night attacks in the Autumn and Winter .
If the Germans had a strategic air reserve in the Winter of 1943,they would not have used it to defend Berlin against the attacks from BC, but they would have spared it to use it on June 6 1944 .
And, there was no major political blow on 29 December when the City was attacked and strongly hurt .