Always reckoned to be a photo-finish (or photo-start) between 'The Topic' in Bradford and 'The Ballads and Blues in London'. MacColl was always sure that it was B&B, but there is no documentary evidence. -Guest
The Topic (or more correctly, the weekly folk singing meeting that fairly soon turned into The Topic Folk Club) is well-established as starting up in September 1956. Peggy Seeger in her letter in the 40th issue of Living Tradition (on the 'sing from your own culture' policy debate) and biography of Ewan MacColl on her website says the B&B was founded in 1953.
In a previous post above I said that Alex Eaton, guiding light of the Topic founding, had referred to the Ballads and Blues, but checking his 1990 Tyke's News article I see he doesn't actually mention the club. He gives precedence to The Good Earth: "Firstly then as to dates. The Topic is certainly the oldest British Folk Club in continuous existence since its inception. The only club founded earlier did not last too long. The Good Earth, 44 Gerard Street, London, started in December 1954 and became the 44 Skiffle and Folk Club in May 1956."
On the other hand Fred McCormick in a review of The Companion to Irish Traditional Music talks about an entry on English clubs: "I was also surprised to find the anonymous author of this piece claiming that the first English folk club to set up was the Topic in Bradford in 1956. Such a claim runs counter to received wisdom, namely that Ewan MacColl and A L Lloyd kicked the entire 'second' revival off with the Ballads and Blues Club in London in 1953. The waters of the early English revival have become muddied with age and I am not sure how much credence can be given to this latter claim. What is incontrovertible however, is that the Ballads and Blues was in existence well before the Topic opened its doors."
On November 7th 1986, incidentally, Peggy Seeger and Ewan MacColl headlined at The Topic's 30th Anniversary celebration, and presumably whoever was there at the time talked about the early days.