Bush was in London on 15 July 1943 to attend a meeting of the British War Cabinet's Anti-U-Boat Committee. Sir Stafford Cripps took him to see Churchill who told Bush that the President had given him his word of honour on full co-operation, and that he was incensed at obstruction by American bureaucrats. Bush suggested that he take up the matter with Stimson, who was also in London. Churchill did so on 17 July, and Stimson promised to submit the matter to Roosevelt. On 20 July, Roosevelt wrote to Bush with instructions to "renew, in an inclusive manner, the full exchange with the British Government regarding Tube Alloys", but since Bush was in London, he did not see this letter for another ten days. Stimson, Bush and Stimson's special assistant, Harvey Bundy, met Churchill, Cherwell and Anderson at 10 Downing Street in London on 22 July. None of them was aware that Roosevelt had already made his decision.