DSI chief Tarit Pengsith said he signed the summonses acting on the advice of the Criminal Court, which earlier rejected the DSI's request to approve warrants for the arrest of a number of PDRC leaders.
The 55 are to be charged with acts of rebellion, inciting unrest and causing a state of chaos in violation of Sections 113, 114, 116 and 215 of the Criminal Code.
They are divided into three groups, summonsed to report to the DSI on 22, 23 and 24.
Those in the first group summonsed to report to the DSI on Jan 22 are: Sathit Wongnongtoey, Chumpol Chulasai, Puthipong Punnakant, Issara Somchai, Witthaya Kaewparadai, Thaworn Senneam, Nathapol Teepsuwan, Akanat Promphan, Anchalee Paireerak, Nitithorn Lamlua, Uthai Yodmanee, Samdin Lertbut, Gen Preecha Iamsuphan, Somkiat Pongpaiboon, Yossak Kosaikanont, Supawat Supiyapanich, Somboon Thongburan, Ratchayut Sirayothinpakdi or Amorn Amornrattananond.
Those summonsed to report to the DSI on Jan 23 are: Jitrapas Bhirombhakdi, Sathit Pitutecha, Sakolthi Pattiyakul, Tossapol Pengsom, Sombat Thamrongthanyawong, Kaewsan Atipho, Jermsak Pinthong, Seri Wongmontha, Kittisak Prokkati, Thanom Onketpol, Chanwit Wiphusiri, Paiboon Nitiwan, Gen Pathompong Kesornsuk, Suriyasai Katasila, Pibhop Dhongchai, Boonyod Sukthinthai and Ong-art Klampaiboon.
The third group, to report to the DSI on Jan 24, are: Somsak Kosaisuk, Phra Phuttha-issara, Savit Kaewwan, Sathit Segal, Kittichai Saisa-ard, Komsan Thongsiri, Sonthiyan Chuenruthainaitham, Pichet Pattanachote, Manmaen Kakarndee, Prakobkij Inthong, Nasser Yima, Pansuwan na Kaew, Suriyan Thongnoo-iad, Samran Rodphet, Nathaya Daengbu-nga, Rangsima Rodrassamee, Taya Teepsuwan, Vachara Phetthong, Adm Chai Suwanphap and Thawil Pliensri.
PDRC leader Suthep Thaugsuban is not included in the list since a warrant has already been issued for his arrest. Phichit Chaimongkol, a core member of the Network of Students and People for Reform of Thailand (NSPRT), is also not included since he had already een arrested and freed on bail.