"Churchill took Mikołajczyk with him to Moscow in early October to resume the Polish-Soviet talks postponed for two months. In the course of a dramatic meeting with Molotov, it was revealed that a year earlier at Teheran Churchill had secretly proposed the Curzon Line as a basis of the future Polish-Soviet frontier. In other words, all the territorial plans and negotiations throughout 1944, which had poisoned relations with Stalin, and had minimised the chances of his co-operation during the Rising, had been conducted on false assumptions. Churchill, shame-facedly admitted his fault, but later turned his rage on the Polish premier whom he had so inexcusably misled. This must be one of the most discreditable episodes of Churchill's career. Mikołajczyk soon resigned; and the close alliance between the British and Polish Governments ceased to function."
warsawuprising.com/paper/davies1.htm
warsawuprising.com/paper/davies1.htm