Lebanese Speaker Nabih Berri called on Monday for parliament to hold a session on June 14 to elect a new president.
Lebanon has been grappling with a presidential vacuum since the end of Michel Aoun's term in October.
The announcement came as the Free Patriotic Movement, one of Lebanon's biggest Christian parties, along with opposition parties, officially declared its support at the weekend for presidential candidate Jihad Azour, following weeks of internal negotiations.
Mr Azour is the head of the Middle East and Central Asia department at the International Monetary Fund and a former Lebanese minister of finance.
He will be facing Suleiman Frangieh, an MP backed by the powerful pro-Hezbollah bloc.
Mr Frangieh is the head of the Marada Movement, a Lebanese political party and a former Christian militia active during the Lebanese civil war. He is considered to be a close friend of Syrian President Bashar Al Assad.
Hezbollah, the powerful pro-Iranian political party and militant group, firmly opposed Mr Azour's candidacy as “a manoeuvre … for the Christian parties to agree among themselves to nominate a person for the presidency”, a spokesman told The National.
Members of parliament have failed so far to agree on a successor for Mr Aoun through the 11 electoral sessions called by Mr Berri.
Mr Berri had previously stated that he would call for a session only if there was “real competition”.
In the eleven electoral sessions, MP Michel Moawad, the previous opposition's candidate, failed to secure enough votes for the presidency, with blank ballots consistently surpassing the votes cast in his favour.
Mr Moawad announced his withdrawal as a candidate on Sunday.