Former Minister and Parliamentarian A.H.M. Fowzie said he would take legal action against the SLFP's decision to expel him from the party.
The SLFP recently decided to cancel Fowzie's membership on the basis that he supported the UNP's campaign at the Presidential election.
Speaking to a local newspaper, Fowzie said his party membership was revoked to allow former President Maithripala Sirisena to enter Parliament.
"If Sirisena wanted to enter Parliament, he could have simply asked him. I would have resigned from my seat to facilitate the move," he added.
Fowzie said his membership had been revoked in an unfair manner, disregarding his long-standing loyalty to the SLFP.
The former Minister had been a member of the SLFP for over four decades.