On December 3, 1964, the parliamentary fraction of LSSP(R) voted alongside the right-wing United National Party and dissidents of the Sri Lanka Freedom Party for an amendment to second throne speech of the SLFP-led government.
In 1966 Samarakkody started a left opposition against Bala Tampoe and the rest of the leadership.
Samarakkody and his supporters left the LSSP(R) following a Special Conference (18–19 April 1968) and formed the Revolutionary Samasamaja Party.
The 1969 World Congress of the Fourth International appointed a Ceylon Commission to discuss with both Samarakkody's group and the LSSP (R), but was unable to resolve the differences.
A Healyite splinter group, formed amongst students in 1968, is now called the Socialist Equality Party.