The Criminal Court has set Aug 14 for handing down a ruling in a criminal case brought against 24 red-shirt leaders and key figures for alleged offences committed during the 2009 political turmoil.
Among them were Veerakarn Musigapong, 71, the former UDD chairman; Jatuporn Prompan, 54, the group's present chairman; Nattawut Saikuar, 44, a key figure; and Weng Tojirakarn, 68, another important UDD member.
The 24 defendants were arraigned on terrorism and five other similar charges stemming from the unrest. They had all pleaded not guilty.
The fuse for the unrest was lit when the Constitutional Court ruled to dissolve the Thai Rak Thai Party in 2007 for allowing former prime minister Thaksin Shinawatra, widely perceived as the party's de facto leader, to control its internal affairs.
The Abhisit Vejjajiva administration later took office on the back of this ruling in 2008 prompting the street protests led by the UDD in 2009. The UDD looked to oust Mr Abhisit and pressure three members of the Privy Council into resigning.
In a separate development, the Criminal Court has scheduled May 14 for the first hearing in the alleged treason case against street protest leader Suthep Thaugsuban and 30 others of his People's Democratic Reform Committee who joined hands to obstruct the election in 2014. Mr Suthep and former Democrat MP Chumpol Julsai also face terrorism charges.