There were certainly secret members of the CPGB within the Labour Party with the knowledge and support of King Street at least until the late 1940s. The onset of the cold war made the position more difficult but the hope remained for Communist affiliation to the Labour Party. This was applied for several times but at the last attempt, I believe in 1944, it came close to success. There were key CP members in positions within the Labour Party who were there furthering the objectives of the CP and although this policy formally lapsed the remnants remained and even within the parliamentary Labour Party there were some who remained very close to the CPGB. I remember John Gollan talking about meetings at the House of Commons into the 1970s with small groups of MPs.

A group of expelled Labour MPs in the 1945-50 period formed an informal group with the Communist MPs Willie Gallagher and Phil Piratin. DN Pritt and John Platts- Mills in particular were closely identified with the CP and regarded as closet members and in the minutes of the last meeting between Stalin and Harry Pollitt Stalin asked Pollitt whether Platts-Mills would formally join the CP. He never did and was eventually allowed back into the Labour Party, but he always remained close to the CP.