It has granted the military sweeping powers amid rising anger and political uncertainty in the capital.
The blast that killed more than 170 people and injured at least 6,000 others changed the face of the city and forced the government to resign.
Before resigning, the government declared a state of emergency in Beirut that granted the military sweeping powers including the power to declare curfews, prevent public gatherings and censor media, as well as refer civilians to military tribunals for alleged security breaches.
The move has been criticised by rights groups and other critics who say the civilian government was already operating with increased powers because of the coronavirus outbreak.
Some pointed to the heavy military crackdown on protesters last week, fearing extended power could lead to increased use of force to silence dissent.
The state of emergency required parliamentary approval.
Parliament is convening outside its regular location to observe social distancing amid a coronavirus surge and because of protests outside the Parliament building by angry Lebanese who want the entire political class to step down.
More protests are expected on Thursday.
The session opened with a moment of silence for those killed in the blast.
It then moved to discuss the resignation of nearly a dozen politicians who quit last week in protest of the government’s handling of the August 4 blast.
A major Christian party bloc is boycotting the session.
It is still not known what caused the fire responsible for igniting nearly 3,000 tons of ammonium nitrate stored in Beirut’s port.
But documents have emerged in the wake of the explosion that show the country’s top leadership and security officials were aware of the chemicals being stored in the city port.
The explosion has fuelled outrage and protests against top political leaders and led to the resignation of the government Monday.
The Cabinet is now in a caretaker capacity.
Parliament is required to approve the state of emergency eight days after it is imposed but it is not clear if the body has technically extended the government decision for 15 days or simply imposed the state of emergency starting on Thursday, human rights lawyer Nizar Saghieh said.
“There is incredible chaos,” he said.
Before resigning, the caretaker prime minister proposed early elections, an idea that was not supported by the Parliament speaker and other political groups.
Since the resignation, there has been a flurry of closed-door meetings and political haggling to form a government that meets the approval of domestic and international powers.
Lebanon’s complicated sectarian-based political system requires the prime minister to be chosen from among Sunni Muslims.
It is not clear if there will be a national unity government – which would mean the participation of all political parties – or an emergency transition government.
