THE RED-SHIRTS

The focus of the red-shirts' campaigning zeal is Thaksin Shinawatra, the prime minister ousted by the military in a September 2006 coup.

By then Mr Thaksin had governed Thailand for five years. He was very popular among the rural poor, because he initiated policies that benefited them, such as funding for health-care and education.

When elections were held 18 months after the coup, this rural support had not changed, even though Mr Thaksin was in overseas exile.
Voters from Thailand's north and north-east returned his allies to power - only to see the government fall to a series of opposition protests and court rulings.
So, in March, the red-shirts came out on the streets of Bangkok. Their formal name is the United Front for Democracy Against Dictatorship (UDD).
Members are mainly rural workers from outside Bangkok. But the UDD ranks also include students and activists who see attempts by the urban and military elite to control Thai politics as a threat to democracy.
The red-shirts say the military ousted an elected government in 2006.
They believe that the court decision that forced Mr Thaksin's allies from power two years later came from a biased judiciary. They say the current government - led by the Democrats - came to power illegally.
The red-shirts feel patronised by the suggestion that rural voters only backed Mr Thaksin because he bribed them - and they deeply resent the fact that the voice he gave them in Thai society has been silenced.
They want fresh elections and some - but not all - want Mr Thaksin back.
Their protest began with a series of sit-ins outside government offices, but quickly escalated.
In April they forced the cancellation of a summit of the Association of South-East Asian Nations (Asean) after storming the summit venue in the seaside resort of Pattaya.
Violence then erupted in Bangkok. Clashes involving troops, protesters and Bangkok residents left at least two people dead and dozens hurt.
On 14 April, as troops massed, the red-shirts called off their protests. Leaders said they feared more loss of life. Three of their leaders are now in police custody; ten others are being sought.
But the anger that triggered their action has not gone away. Red-shirt leaders say they plan to continue the fight.
The attempted assassination on 17 April of yellow-shirt leader Sondhi Limthongkul will elevate tensions further.
There is no indication yet as to who was involved, but the attack does raise fears of direct clashes between the reds and yellows - something that has largely been avoided so far.