 When World War II broke out in September 1939 the LSSP opposed the "second imperialist war".The LSSP played a major role in a wave of strikes in 1939/40 and consequently it was proscribed in 1940 and its leaders Colvin R. de Silva, Philip Gunawardena, N. M. Perera and Edmund Samarakkody arrested in June 1940.Leslie Goonewardene evaded arrest and went into hiding.