The RSP(L) was formed as a splinter group of the Revolutionary Socialist Party (RSP) in Kerala in 2016. The party leader at the time of its formation was Kovoor Kunjumon, formerly an important RSP leader in Kerala. RSP(L) is the part of CPI(M) led Left Democratic Front (LDF). The party won one seat (won by Kovoor Kunjumon) in the 2016 and 2021 Kerala Legislative Assembly election.