Former Deputy Minister Vinayagamoorthi Mutalitharan alias Karuna Amman has decided to join the TULF, led by former Parliamentarian V, Anandasangaree.
Karuna Amman, a former Vice Chairman of the SLFP, was the founding leader of the TMVP following his defection from the LTTE.
Karuna has also decided to resign from all the positions he held as a member of the SLFP.
The "official reason" behind Karuna Amman's resignation from the SLFP is the party's slow approach on the "Tamil question".
Karuna and his erstwhile associate Pilleyan are now under investigation over a number of crimes, committed under the watch of some top echelons of the previous regime.
Pilleyan was recently arrested for killing former TNA MP Joseph Pararajasingham during the Christmas day mass at a church in Batticaloa in 2005.
At the time Pararajasingham was killed, Karuna and Pilleyan were working together as the leader and the deputy leader of the TMVP.
They had close links with the Sri Lankan military.