What was it that Bert Harris said after the end of the War?
In a letter to the head of Avro after the war, Marshal of the Royal Air Force Sir Arthur Harris, the Commander in Chief of Bomber Command, said of the Lancaster:
“I would say this to those who placed that shining sword in our hands: Without your genius and efforts we could not have prevailed, for I believe that the Lancaster was the greatest single factor in winning the war.”
RAF BBMF - The Lancaster
As has been said previously, it's unlikely that a single aircraft or any other weapon "saved Britain". More likely it was the combined effect of several types of sea, land and air machines working together intelligently and with imagination by the men commanding and operating them.