The People's Alliance for Democracy (PAD) (Thai: พันธมิตรประชาชนเพื่อประชาธิปไตย; also called the National Liberation Alliance - กลุ่มพันธมิตรกู้ชาติ, the National Liberation Party - พลพรรคกู้ชาติ, and the Yellow Shirts - คนเสื้อเหลือง) was originally a coalition of protesters against Thaksin Shinawatra (ทักษิณ ชินวัตร), the former Prime Minister of Thailand. Its leaders include media-mogul Sondhi Limthongkul (สนธิ ลิ้มทองกุล), Chamlong Srimuang (จำลอง ศรีเมือง),ธhe secretary of the Thailand's Federation of Government Owned Enterprise Labour Somsak Kosaisuuk (สมศักดิ์ โกศัยสุข),The Professor at Nakhon Ratchasima Rajabhat University Somkeit Pongpaibul (สมเกียรติ พงษ์ไพบูลย์), and former ISOC leader Pallop Pinmanee (พิภพ ธงไชย). It was one of the chief players in the Thailand political crisis from 2005 to 2006. The PAD consists of middle and upper-class Bangkokians and Southerners, supported by the conservative elite, factions of the Thai Army, and state-enterprise labor unions.
The People's Alliance for Democracy has been re-established in Thailand on March 28, 2008 at Thammasat University auditorium. Several issues was raised by the PAD, including the Prime Minister Samak Sundaravej ties to Thaksin Shinawatra (ทักษิณ ชินวัตร), ties between some People's Power Party members and the banned-Thai Rak Thai party, and attempts to amend the 2007 Constitution. Among the amendment proposed was removal of Article 237 which would dissolve a political party if one of the executives was involved in vote buying. Yongyuth Tiyapairat, People's Power Party executive who was also the Parliament president after the election, was being tried for vote buying. Yongyuth was later found guilty by the Supreme Court on July 8, 2008.
Demonstration by PAD started on May 25, 2008 at Democracy Monument on Ratchadamnoen Road to protest the proposal for constitution amendment. The rally attracted ten thousand supporters.As the rally went on, PAD announced their effort to collect signatures to request removal house representatives and senates who supported the amendment on May 30, 2008.The next day Samak expressed on government-run NBT television channel his intention to dissolve the rally by force. In reaction to Samak's speech, PAD issued announcement against the government's move.