Beirut: Lebanon was plunged deeper into political turmoil after the Syrian-backed opposition said it would boycott a Friday presidential election.

French-led mediation failed forge agreement between Lebanon’s rival political parties on who would succeed pro-Syrian president Emile Lahoud, whose term ended at midnight.

The anti-Syrian majority plans to go to the election in parliament despite the boycott, which denies the chamber a two-thirds quorum for a vote already postponed four times.

Many fear Lahoud's departure from office with no deal could result in two rival administrations and violence in a country still rebuilding from its 1975-1990 civil war.

The army has boosted security and warned against any internal strife. Both sides have accused each other of arming supporters.

Lahoud disputes the legitimacy of the Western-backed government of Prime Minister Fouad Siniora and is expected to take some kind of step before he leaves office.

The anti-Syrian majority argues that Siniora's government should automatically take over presidential powers until a new head of state can be elected.