[1] In 1934, Kaye joined the Communist Party of Great Britain (CPGB), initially through the National Unemployed Workers' Movement; he was present at the Battle of Cable Street, and gave speeches opposing the British Union of Fascists.
[1][4] Kaye was soon appointed as CPGB branch secretary for Hackney and, as a result, he decided not to volunteer for the International Brigades in the Spanish Civil War.
[4] Although initially he experienced hostility from the church, he gradually won them over; the Franciscan Neville Palmer declared that "it is not a sin to vote for Solly Kaye" and John Groser claimed that "Solly Kaye is the one remaining prophet of the Lord amid all the prophets of Baal on Stepney Council".
[8][9] Alongside his council post, Kaye gave regular speeches in Finsbury Square, and worked as a copywriter, then later as a woodwork teacher at Acland Burghley School.
[1][4] He spoke about the anti-fascist movement of the 1930s at events in the late 1980s, to counter the rise of the British National Party.