Winston Churchill had many endearing qualities and one of them was his intense loyalty to institutions. He did not only serve as a politician, he loved the institution of the House of Commons.
It is not a huge surprise therefore, that Churchill co-founded a dinner club where politicians could enjoy themselves once every other week (on Thursday evening) when parliament was in session. From Wikipedia
Churchill, who in 1910 was Liberal Home Secretary, and barrister and Conservative MP F. E. Smith had not been invited to join the venerable political dining club known just as The Club. Although both had friends in it, the members thought Churchill and Smith too controversial. So they established their own club, to be called by contrast “The Other Club”.
In 1911, Winston Churchill, Secretary of State for the Home Department in the Liberal government of H.H. Asquith, and his closest friend, Conservative MP and barrister F.E. Smith (later Lord Birkenhead), desired to join The Club. Legend has it that both were blackballed, considered too brash and controversial. The journalist Sir Colin Coote, The Other Club’s sometime secretary and historian, found no documentary evidence of this, but considered it possible. Churchill’s 1904 defection to the Liberals had alienated him from the Tories; Smith was just deemed unpleasant—and altogether too pugnacious. (In court, when a judge called him offensive, F.E. replied, “As a matter of fact we both are; the difference is that I’m trying to be, and you can’t help it.”)
Given that Churchill also loved the finer things in life, it is also not a huge surprise that these dinners would be hosted by the Savoy Hotel. Here is a fun caricature of an event
It was called the “Other Club” (the first club being the commons) and It has continued on from 1911, even through the wars. There were few rules – just no speeches and no politics. And pot au feu was served at each meal, apparently a Churchill favorite.
After FE Smith passed on in 1930, Churchill was sole arbiter of who could join. And it would appear that he made his selections mainly based on their potential for entertaining conversation. That included Aristotle Onasis, who Churchill met in the South of France and who apparently made quite an impression. Atlee was never invited.