Police charged Charoen Insuriya, 71, with premeditated murder. He allegedly used a large chopping cleaver to hack to death Pud Jaimul, 56, at Mr Charoen’s house in tambon San Don Kaew late on Friday night.
Mr Charoen invited Pud and several other neighbours to his house for a meal and a drink.
The atmosphere was initially friendly but as the night wore on, tension built when Mr Charoen brought up politics, police said.
A supporter of the People’s Democratic Reform Committee, Mr Charoen told his guests the anti-government movement leader Suthep Thaugsuban has helped many farmers caught in the rice-pledging scheme.
Pud, a red shirt member, however, insisted caretaker premier Yingluck Shinawatra was being framed for her role in the rice-pledging policy.
The men then had a heated argument before Mr Charoen took out the cleaver and attacked Pud, who died at the scene.
Police said the two men were drunk during their argument.
Pud sustained deep hacking wounds on his forehead and the back of his head.
Pol Col Chaturong Paeto, superintendent of Mae Tha district police, said Mr Charoen denied the charge. He has been remanded in police custody.
The district police chief said he had evidence and witnesses to the crime.