The full devastation that the Allies were prepared to unleash on the Channel Islands in 1942 to regain a foothold in Europe has been revealed for the first time.

Two years before the liberation of Europe from German forces in June 1945, Churchill, Stalin and Mountbatten hatched a plan to retake Jersey, Guernsey and Alderney from the German occupiers.

Their aim was to regain a bridgehead for an assault on France, and distract the Germans high command from its offensives to the east.

Until now, the hugely detailed plans