Most military officers in the agency believe Thursday's incident was set up for political purposes by Thaksin's close associates inside and outside Isoc.

Among Thaksin's clique in the agency is Maj-General Chalermchai Wiroonphet, who was transferred to Isoc as a lenient punishment for his role in the crackdown on the Tak Bai protest in October 2004 that led to 85 civilian deaths.

Sources said many Isoc officials wondered whether Chalermchai, now assistant director of Isoc's intelligence department, knew about the plan. Police have said the explosive-laden car found near the premier's residence was driven there early in the morning from the Isoc headquarters a few kilometres across the Chao Phya River.

The officials suspect the masterminds chose Lieutenant Thawatchai Klinchana, an Isoc officer, to drive the car as he could be linked clearly to General Pallop Pinmanee, who was Isoc deputy director until he was sacked over the alleged plot.

Pallop has admitted that Thawatchai was formerly his driver and later worked for him gathering intelligence in the deep South.

Outside Isoc, National Intelligence Agency Director Pol General Jumpol Manmai is the main conductor to direct the drama and spin information to create public perception of a threat to Thaksin's life, the sources say.

Officials at the former anti-Communist agency say Thaksin targeted Isoc for many reasons.

First, it is one of the most vulnerable military agencies since it is not under the Armed Forces nor does it have its own soldiers, meaning there is little chance of it retaliating.

Second, as a retired Army general Pallop is toothless. Firing him from the position on Thursday will have no strong consequences for Thaksin as the post of deputy director is a political appointment under the premier.

Third, Pallop is a classmate of Maj-General Chamlong Srimuang, one of the key leaders of the People's Alliance for Democracy, the major force in organising street protests against Thaksin over past months.

Pointing the finger at Pallop for the alleged assassination plot automatically puts blame on Chamlong. Pallop has admitted to sending Isoc officers to protect Chamlong during recent street protests.

Last but not least, Thaksin wanted to get rid of Pallop so that he could make the civilian volunteer network it built up during the anti-Communist war of the 1970s and '80s a political support base for the Thai Rak Thai Party in the coming general election.

"The national volunteer network is Isoc's main asset. Gen Pallop considers it as national security asset and does not want any particular party to use it for political gain," an Isoc official said on condition of anonymity.

Isoc's civilian network was reduced after the anti-Communist war but saw a revival during Thaksin's war on drugs and the latest resurgence of violence in the deep South.

The agency currently plays a significant role in psychological warfare to gain popular support for the government in its struggle with militants in the South, where Thaksin's Thai Rak Thai Party has fared badly in previous elections.

Supalak Ganjanakhundee

The Nation