OK, this is hardly exhaustive, but I was reading this NYRB piece (sub. req.) titled “The Mouse That Roared,” which is a review of a book about former British PM Clement Attlee. Most of the article has nothing to do with WMD, but I read this paragraph with interest:
At the end of the war, Attlee took a strong line in favor of dismembering the German state, even if he stopped short of Henry Morgenthau’s plan for “pastoralizing” the country. He wholeheartedly supported Truman on the dropping of the atomic bomb and instantly concluded that Britain must have atomic weapons of its own and be prepared to use them. Fearful that his Labour colleagues might not support him, he set up a secret Cabinet committee, GEN 163, to authorize work to begin before any objections could be raised. The committee met only once, on January 8, 1947, and its decisions were not communicated to the Cabinet, then or later. Similarly, neither Cabinet nor Parliament got to hear of Attlee’s agreement with James Forrestal, the US secretary of defense, to station three groups of large bombers on British soil.
This UK Govt fact sheet explains that
Wartime UK-US nuclear collaboration was brought to an end by the 1946 US Energy Act (the McMahon Act), following which, in 1947, the Attlee Government decided to resume an independent UK programme to develop an atomic weapon. The UK successfully tested its first atomic bomb in October 1952.
A chapter in this 2001 report cites a record of the 1947 meeting:
There is a record of that meeting in the UK National Archives, but it seems not to be available online:
