The threat was issued by Sondhi Limthongkul, one of the PAD leaders, after riot police fired tear gas on protesters early in the morning, leading to more than 70 injuries. The deadline passed without any occurrence.
Prime Minister Somchai Wongsawat ordered police to disband the crowd and clear the way for the scheduled debate on Tuesday.
The PAD had set up a blockade to prevent Parliament from convening and Mr. Somchai from making his policy statement. Under Thai law, a new government is not able to function until a policy announcement is made before Parliament.
Thai officials state that only tear gas was used, however PAD supporters say Thai police also used bombs and guns against the unarmed group. PAD claims that more than 160 were injured, including one woman being blinded and one man losing a leg.
The 30-year-old Mr Thanya Khoonkaew was taken to Vajira Hospital where doctors say his bone in the left leg was shattered, requiring his leg to be amputated from the knee down.
The injury suffered could only be sustained by a bomb, and not tear gas grenades, the PAD stated.
Images of Thai police firing tear gas grenades directly at the protesters were shown on ASTV, a satellite TV channel owned by Mr Sondhi.
After the police successfully cleared a path, Mr Somchai opened the Parliamentary session while the PAD regrouped outside.
When demonstrators surrounded the Parliament building again they cut off the electricity and water.
According to the Associated Press, Parliamentarians were afraid to leave the after the session ended. "We are under siege now," said Kuthep Saikrajang, a spokesman of the People's Power Party. "But we will have to figure out a way to get out without using force."
By early evening riot police started firing rounds of tear gas at the crowd. PAD announcers urged law enforcers not to follow the orders of the government, which, they said, would harm the demonstrators, including elderly and young children.
The police fired tear gas canisters, slowly pushing the demonstrators back.
Reports in Thai from the Manager website, the newspaper produced by ASTV’s parent company, state that the latest “round of assault” from Thai police caused four demonstrators to suffer crippling foot injuries from explosives, and one to end up in hospital with severe facial, hand, and leg injuries.
