Mr Abhisit said in his lawsuit that he was slandered by Mr Jatuporn during his public speech to a gathering of more than 10,000 people in Don Muang area on May 10, 2009.
Calling Mr Abhisit a murderer whose hands were soaked with blood, Mr Jatuporn said during the speech that the former premier ordered soldiers to open fire at civilians – an action which deserved execution.
Mr Abhisit said the Red Shirt core leader made false statements against him and violated Section 326, 328 and 332 of the Criminal Code.
In turning down Mr Abhisit’s lawsuit, the court said the defendant and plaintiff were political opponents and retaliations between both parties during an election campaign were normal under the democratic system.
Mr Abhisit’s attorney said he would appeal the court’s verdict.
Mr Abhisit has filed four libel cases against Mr Jatuporn, two of which the defendant was already found guilty.
The Criminal Court earlier sentenced Mr Jatuporn to six months’ imprisonment and a Bt50,000 fine for each case. He was put on a two-year probation instead of receiving a jail term.