Colombo, July 13 : A three-pronged battle is set to take place for the selection of the next Sri Lankan President by approval of Parliament on July 20, state media reported. Prime Minister Ranil Wickremesinghe, Sri Lanka Podujana Peramuna (SLPP) MP Dalles Alahapperuma and Opposition Leader Sajith Premadasa mull the submission of nomination papers to run for presidency in the secret ballot. The Presidential post fell vacant prematurely in Sri Lankan history on one occasion -- the assassination of President R. Premadasa on May 1, 1993 . It is now slated to be vacant after the resignation of President Gotabaya Rajapaksa as already announced by him, the Daily Mirror reported. Parliament will take a secret ballot on July 20 to elect the new President. According to Daily Mirror sources, Wickremesinghe will contest for the post to serve the rest of the current presidential term. A section of the SLPP is planning to back him while another faction of the SLPP, including the 10-party alliance supports Alahapperuma. Earlier, the Samagi Jana Balawegaya announced that Sajith Premadasa will be its presidential candidate, the Daily Mirror reported. The candidates who get more than 50 per cent of valid votes will become the President. Unless any of the contestants cross the 50 per cent mark, the preferential votes marked by the MPs will be counted. According to informed sources, the Janatha Vimukthi Peramun (JVP) has taken up the position that a neutral MP with no future electoral ambitions should be appointed the next President, the Daily Mirror reported. The party says Speaker of Parliament Mahinda Yapa Abeywardane should be appointed. The JVP believes the appointment of a political leader with future presidential ambitions will work for the interests of his party with the next election in mind. /IANS