Already mired in political and economic crises, Lebanon is now also without a president after Michael Aoun's mandate expired without a successor.

Aoun's six-year term, that came to a close on Sunday, was marred by mass protests, a painful economic downturn and the August 2020 mega-explosion of ammonium nitrate that killed hundreds and laid waste to swathes of the capital Beirut.

Today, headed by a caretaker government, Lebanon is unable to enact the reforms needed to access billions of dollars from international lenders to help save an economy in free-fall since late 2019.

In Lebanon, power is divided among the country's main sects -- none of whom hold a clear majority.

- Why is there no president? -

Aoun left the presidential palace Sunday, a day before the end of his term, cheered on by a few thousand supporters.

In Lebanon, lawmakers vote in parliament for president.

Parliament has held four rounds of voting since last month, with no candidate garnering enough support to succeed Aoun.

Some lawmakers accuse the powerful Iran-backed Shiite Hezbollah movement and its allies of obstructing the vote to negotiate with other blocs.

They adopted a similar tactic in the last election by boycotting the vote in parliament -- a move that left Lebanon without a president for more than two years, until Aoun's 2016 win.

Without a dominant party in parliament, decisions like electing a president, naming a prime minister or forming a government can take months or even years of political horse-trading, sometimes even leading to violence.

- Who rules the country? -

The president's powers fall to the Council of Ministers if he leaves office without a successor.

Aoun signed on Sunday a decree formalising the resignation of premier Najib Mikati's government, in a caretaker role since legislative elections in May.

The move exacerbates a months-long power struggle that has paralysed the government.

Mikati retorted that his government will continue his work in caretaker capacity as usual, but that cabinet will only meet "for urgent matters".

Experts said it was part of ongoing political arm-wrestling between Aoun and the premier.

A cabinet in a caretaker role cannot take important decisions that might impact the country's fate.

"This greatly affects the government's work, because it cannot issue decrees or take any decisions that require collective consensus," a source close to Mikati said.

This includes decisions needed to kickstart offshore gas exploration and extraction, after Lebanon demarcated its sea border with Israel last week.

- What happens next? -

Parliament Speaker Nabih Berri might invite political parties for a national dialogue, so they can agree on a new president, a lawmaker close to him said on the condition of anonymity.

"No party can impose a candidate," he said. "Therefore the only solution is to reach a consensus, otherwise the presidential vacancy is likely to last."

But such initiatives have failed in the past.

So far, lawmaker Michel Moawad, 50, has garnered the most support in parliament, mostly from those opposed to Hezbollah.

But without Hezbollah's support, Moawad's chances of becoming president are slim.

Hezbollah has not officially endorsed a candidate, but Sleiman Frangieh, 57, a personal friend of Syrian President Bashar Al-Assad, was always considered one of the group's preferred choices.

But Hezbollah's Christian ally, Aoun's Free Patriotic Movement (FPM), will not back Frangieh.

Gebran Bassil, 52, the FPM's leader and Aoun's son-in-law, is also vying for the presidency.

Others have also floated Lebanon's army chief Joseph Aoun, 58, as a potential candidate for the presidency, in a country where army commanders have snatched this post several times.