Rally leader Suthep Thaugsuban on Monday night refused to back down after the PM invokes special internal security laws in Bangkok and other neighbouring provinces.
He said he would not disperse the rally and instead he called on more people to join the anti-government rally. The Internal Security Act prohibits people from gathering.
Suthep said the government had rejected the power of Constitutional Court which meant rejecting the charter itself, making the government illegitimate.
He called for people and government officials to defy to the government. Unless lots of people join in the protest, Suthep said he would not flee but sit still and allow officers to arrest him.