In the early part of the Second World War, the Polish Government in Exile (often in concert with the Czechoslovak government) sought to maintain pressure on the British Foreign Office to respond to war crimes. The chapter examines the statements made by Allied governments, from the Anglo–French–Polish statement of April 1940 to the publication of Punishment of War Crimes (2) in late August 1943. It analyses the diplomatic steps taken by the Polish Government in Exile to press for an Allied response to German atrocities. The chapter charts the path to the important St James’s Palace Declaration on Punishment for War Crimes of 13 January 1942. The 10 December 1942 Polish Note to Allies and the 17 December 1942 United Nations Declaration that publicly and officially recognised Germany’s policy ’to exterminate the Jewish people in Europe’ are also discussed.