Leader of the House Minister Lakshman Kiriella said 15 MPs of the SLFP would join the UNP before the next Presidential election.
Speaking to Asian Mirror, Kiriella said another group of SLFP MPs would join the UNP.
However, the Minister refused to reveal the names of the MPs who are planning to join the UNP.
Kiriella also added that only President Maithripala Sirisena would remain in the SLFP.
President Sirisena is currently the leader of the SLFP and the party commands the support of nerly 25 MPs in the House.