By Alastair Leithead
BBC Asia correspondent, Bangkok
Protester Pollawat Srichakkote wants a 'perfect democracy'
Thailand's political protesters are a colourful bunch and today was the day of the reds.
It is hard to say exactly how many crammed into the normally busy streets surrounding Government House, but they came in their tens of thousands.
The atmosphere was more carnival than confrontational - at least during daylight hours - as those leading the demonstration gave rousing speeches and played loud music to the cheering crowds from a stage constructed opposite the seat of government.
Bicycle vendors barbecued pork sate and pieces of curious-looking seafood as pick-up trucks drove around dishing out bottles of water and hats to keep the sun off - red hats of course.
There is a strong sense of co-ordination to the reds' movement now - they were seen as being far less organised or resourced than the yellow-shirted demonstrators from last year.
All spoke with passion about why they had come and what they wanted - the prime minister to resign and elections to be held.
Pollawat Srichakkote travelled for five hours by road from Surin in the north-east of the country and said he had come to call for democracy in a Thailand divided between rich and poor.
We are showing our strength - it is us, the people, who are the owners of Thailand
"I want a more perfect democracy that is accepted by everyone in the world and for us to move forward," he said.
"The rich always do things to benefit themselves - it doesn't go to the brothers and sisters in society."
The most obvious icon amid the placards and signs was Thaksin Shinawatra, the prime minister deposed in a coup in 2006 and now a fugitive from Thai justice who has been stirring up the crowds for the past two weeks.
His video-linked speeches from exile have pushed the red-shirted demonstrators to a new level by naming one of country's most important statesmen as the orchestrator of that coup.
The red versus yellow divide is not just about one man - the red shirts broadly represent the poorer, more rural people who were insulted by the rhetoric the more elitist-supported yellows used in saying they did not understand politics and that the popular vote should be diluted.
That has not stopped those from Bangkok from joining a campaign which they hope will increase democracy.
Samita Khunsirasa said she came to the protest to demand that parliament be dissolved and new elections be held.
"We are showing our strength - it is us, the people, who are the owners of Thailand," she said.
"The last two prime ministers came from the people and they were prevented from working so we are here to show what we need is real democracy.
"The reds are not violent - red is the colour of the blood of real democracy."
The last two prime ministers were supporters of Thaksin Shinawatra and the court decision which led to the end of the yellow protest saw Abhisit Vejjajiva from the Democrat Party take control of the country.
Hopes for an 'improved society' prompted Onbanya Shellshan to rally
The protesters who came from across Thailand for the demonstration - young and old - said the way he came to power was not democratic.
Onbanya Shellshan had joined the protest with her friends: "In society there is a democracy for the very few which is unfair.
"We want a return to full democracy and for society to improve for everyone."
Anger has been mounting amid the reds as their movement has gathered momentum, but the police have been keeping a low profile - making their presence felt, but keen to avoid a confrontation.
This weekend leaders from across Asia will be arriving in Thailand for a summit meeting of the Association of South East Asian Nations and major players, including China and Japan.
The meeting was postponed from the end of last year because of the political crisis when yellow-shirted demonstrators forced a change of government after blockading Bangkok's airports and occupying Government House.
The reds are now copying their tactics in the hope of pushing for a similar outcome but the prime minister has said he will not stand for civil strife and has warned the red-shirts to keep their rallies peaceful.
As the demonstrations began, he said he would neither step down nor hold new elections.