Red-shirt protesters of the Radio Broadcasters for Democracy movement were heading to the parliament Wednesday with the intention of submitting a letter to the senate speaker demanding the removal of the nine Constitution Court judges.
The protesters, many of them just arrived from other provinces, gathered on Wednesday morning on Chaeng Wattana road in front of the government offices complex.
They began to move along Chaeng Wattana road about 10am on pick-up trucks and motorcycles.
Sornrak Malaithong, the spokesman of the movement, said after submitting the letter the protesters would disperse. They would split up and travel separately to about 20 provinces to gather signatures to back the impeachment petition.
Pol Col Pong Sangmurin, the Thung Song Hong police chief, said three companies of metropolitan police had been deployed to provide security and facilitate traffic flow along the route being taken by the protesters.
Pol Maj-Gen Prinya Chansuriya, a deputy Metropolitan Police chief, said he did not believe the number of protesters would reach 100,000, as predicted by their leaders.
However, 18 companies of police, about 2,700 personnel, would be on stand by for deployment if needed until the protest ends, he said.
Reports said that after leaving the government offices complex on Chaeng Wattana road, the protesters intended to proceed along Vibhavadi Rangsit road to the Lat Phrao intersection, Phahon Yothin road, then Victory Monument, Ratchawithi and U-thong Nai roads.
They were expected to arrive at the parliament at about 1pm.
Along the way, the protesters would also file a complaint with Thung Song Hong, Prachachuen, Bang Sue, Phayathai and Dusit police stations against the Constitution Court judges for violating Section 157 of the Criminal Code.