Lower House deputy speaker Charoen Chankomol said security measures will be reinforced from Monday and emergency exits will be specially provided at the rear of the Parliament compound in case the entrance is blocked by demonstrators.
A no-confidence debate against Prime Minister Yingluck Shinawatra and three members of her cabinet is set to take place Nov 25-26 to be followed by a vote Nov 27.
Political activists of the anti-government Pitak Siam group vowed to rally at the nearby Royal Plaza on Nov 24 and the possibility of the demonstration dragging on was not ruled out.
Mr Charoen said apart from 300 police assigned to Parliament, police will also be deployed at major locations outside the compound including the Royal Plaza, Dusit Zoo and three main roads around Parliament.
All tents in front of Parliament will be removed, he said, noting that it was unnecessary to request military personnel to cope with the situation.
First Metropolitan Police Commander Vicharnvat Borirakkul said police are almost 100 per cent prepared for their mission.