The latest twist will unfold in parliament on Wednesday, when lawmakers will try for a 12th time to elect a successor to Michel Aoun, a Hezbollah-allied politician whose term ended in October.

The attempt by groups including Hezbollah's opponents to elect Azour, an ex-finance minister and the IMF's Middle East director, is expected to fail because Hezbollah and its allies have enough seats to deny a two-thirds quorum.

"We will obstruct for all to see," a senior Hezbollah-allied politician told Reuters, adding that Lebanon would then face an "open-ended crisis".

Hezbollah officials say the movement and its allies are exercising their constitutional right to block Azour's election.

The tussle has underlined the dim chances of a president being elected soon, leaving Lebanon drifting further from any steps towards remedying a devastating financial meltdown that has been left to fester since 2019.

The power vacuum - with neither a head of state nor a fully empowered cabinet - is unprecedented even for Lebanon, a country that has known little stability since independence.

With the presidency reserved for a Maronite Christian, the standoff also risks exacerbating sectarian tensions: Lebanon's two biggest Christian parties have rallied behind Azour, while Shi'ite Hezbollah and its Shi'ite ally Amal oppose him.

As political splits deepen and the state endures its worst crisis since the 1975-90 civil war, analysts say a deal may now require the kind of foreign intervention that has imposed compromise on its fractious parties in the past.