Arrivals quickly set up temporary shelters and cooked dinners in anticipation of a final bid to oust the Abhisit Vejjajiva administration and the old bureaucratic elite.

Makeshift toilets were being installed by protesters called the red shirts to supplement those provided by the Bangkok Metropolitan Administration, and many food stalls quickly sprang up.

As night fell some traded stories, while others went to listen to the main stage's speakers on Phan Fah Bridge, which became a sea of red shirts.

"The line of cars was really long," said one female red shirt to a male fellow protester.

Both ends of the lengthy rally site along Rajdamnoen Avenue - Sanam Luang and the Royal Plaza where most of government offices including the parliament house and the royal palace were situated - soon became crowded car parks. At Sanam Luang, a park where protests are usually held, a stage was set up by little-known red-shirt members for them to take turns going up to attack the government.

"We can't lose this time. But if we lose, we can expect to stand as equals. The media and academics look down on us, but people with a Grade-4 education have brains too," said an on-stage voice.

Although the atmosphere was relaxed and full of buzz, some red shirts were feeling distrustful of the authorities and were worried that dirty tactics could be employed by the government to make it look like the red shirts had started violence during the night.

"We must keep vigilant tonight. They know more red shirts will arrive tomorrow and maybe they want to stop us tonight and create a situation to justify a clampdown," said one female red shirt from Bangkok, who asked not to be identified.

For the same reason, many red shirts decided not to park their vehicles at designated areas provided by the government for fear that weapons or bombs may be planted and the blame placed on them.

A 7-Eleven convenience store on Rajdamnoen, fearing drink-fuelled violence, put up signs stating it was not selling alcohol for the time being.