N.M. Perera and Philip Gunawardena, who had opposed a merger into the BLPI, reconstructed the LSSP as an independent party.
The latter group functioned as the Ceylon section of BLPI and was led by Colvin R de Silva, Leslie Goonawardene and Edmund Samarakkoddy.
The LSSP wanted to build a mass-based party and accused the BSP of being introvert doctrinaires.
The BLPI-affiliated BSP became an independent party in 1948, and was recognized as the Lankan section of the Fourth International, when the BLPI was dissolved.
When the group around Anil Moonesinghe split from the LSSP in 1982, he charged that the party had been taken over by the BSP faction.