Lebanese lawmakers failed for a fourth time to choose a new head of state on Thursday and will try again in a week’s time, only three days before President Michel Sleiman’s term ends.

Lebanese lawmakers failed for a fourth time to choose a new head of state on Thursday and will try again in a week's time, only three days before President Michel Sleiman's term ends.

Politicians say they expect disagreements over Sleiman's replacement to drag on for months after he leaves office.

Any candidate would have to get support from the two main political blocs - March 8 alliance and the rival March 14 coalition - to win the necessary majority from parliament's 128 deputies.

Thursday's vote was called off after March 8 deputies boycotted the session, leaving it without the two-thirds quorum needed for the vote to go ahead.

Under the country's religion-based power-sharing system, the president must be a Maronite Christian, a sect that is itself divided on its support for March 8 and March 14.

Some lawmakers from the March 14 coalition have warned that if no president is elected before Sleiman's term ends they will boycott parliament, leading to further paralysis in the country of 4 million people.

The deadlock comes two months after Prime Minister Tammam Salam ended a year-long government vacuum by winning a vote of confidence in his new cabinet.

Lebanon also has to deal with electricity outages, decaying infrastructure and public sector wage disputes that brought thousands of protesters onto the streets on Wednesday.