Tens of thousands of red-shirted anti-government protestors are converging on Bangkok, vowing to oust the Thai government by means of a mass demonstration.
They are coming from rural areas to the north of the capital, the heartland of former Prime Minister Thaksin Shinatwatra.
So far, the atmosphere is peaceful, although thousands of police and soldiers have been mobilised to maintain order.
“The government must grant us justice. We want democracy back. This government is illegitimate because is was not properly elected.” said one demonstrator.
The Red Shirts, also known as the United Front for Democracy Against Dictatorship, oppose the 2006 military coup which ousted Shinatwatra.
They believe forcing the government out of power could pave the way for his pardon and return from exile in Dubai.
Its hoped a million protestors will turn up. The prospect of even tens of thousands has rattled nerves in Bangkok.
The protestors say talk of violence is just scaremongering, but the government insists the threat is real.