Saad al-Hariri is expected to be named Lebanon's prime minister on Monday, but political rifts look set to hinder agreement on a new government badly needed to rescue the country from a dire economic crisis.
Hariri, a Western ally and the leading Sunni Muslim politician, is widely seen by politicians as the only candidate for the post. He quit the job in late October under pressure from protests against the political elite that has overseen decades of corruption and bad governance.
But he is at odds with Iran-backed Shi'ite Muslim Hezbollah movement and its allies, including President Michel Aoun, over the make-up of the next government.
Lebanon needs a new government to pull it out of the worst economic crisis since its 1975-1990 civil war. Foreign donors will only help after there is a cabinet that can enact reforms.
Hariri wants to lead a cabinet of specialist ministers which he says would be able to tackle the crisis and attract foreign aid, while his opponents want a combination of politicians and experts.
Aoun's formal consultations with lawmakers to designate the premier, postponed from last week, are scheduled to take place on Monday despite the dispute.
"It should be clear to anyone who might nominate Hariri tomorrow that he will only form a government of specialists," a source close to Hariri told Reuters.
Aoun is required to choose the candidate with greatest support among parliament's 128 lawmakers.
Though it was not immediately clear how many lawmakers would back Hariri, political sources said he would most likely be picked, barring any last-minute surprise in Lebanon's volatile politics.
Attempts to reach compromise deals on other candidates for the job of prime minister - reserved for a Sunni in Lebanon's sectarian power-sharing system - have failed.
Hundreds of people protesting against the ruling elite returned to central Beirut on Sunday, despite a fierce crackdown by security forces near parliament the previous night. The security forces had fired tear gas and rubber bullets overnight at demonstrators in clashes that wounded dozens.