Socialist Party of Sri Lanka
The Socialist Party of Sri Lanka, which has declared fraternal relations with the League for the Fifth International in May 2007, is an Autumn 2006 split from the United Socialist Party in Sri Lanka which is part of the Committee for a Workers' International. The party has members in several unions, including a health union. A representative of the League for the Fifth International visited them in spring 2007, where they signed documents of fraternal relations.
Popular environmentalist and social activist Ajantha Perera was nominated as the party's Presidential candidate for the 2019 Sri Lankan presidential election. She also became the only female Presidential candidate to contest the 2019 elections and the first such instance sice 1999.
Electoral History
| Election year | Election | Votes | Vote % | Result / Remarks |
| 2018 | Local | 1,522 | 0.01% | |
| 2019 | Presidential - Ajantha Perera | 27,572 | 0.21% |