Maithripala is said to have cautioned Rajapaksa saying that any stubbornness on his part to cling on to the post will be met with severe opposition.
Maithripala made his stance clear to Rajapaksa during a meeting held at the Parliament Speaker's (Chamal Rajapaksa) official residence in Colombo on January 14.
The meeting was also attended by several senior stalwarts of the SLFP and went on for several hours.
At the end of the meeting Rajapaksa was compelled to fall in line with the will of the majority of SLFP members and hand over the party leadership to Maithripala.
Likewise the Central Council of the SLFP and its All-island Committee are expected to meet this afternoon to bestow the leadership of the party on President Maithripala Sirisena.