The Supreme Court on Thursday rejected a second application for bail for Boonsong Teriyapirom, a decision which leaves the former commerce minister behind bars.
Boonsong's lawyer, Narin Somnuek, said the Supreme Court's Criminal Division for Holders of Political Positions ruled there were no grounds for his client's temporary release from prison to appeal the judgement.
Boonsong showed stress after he informed him of the court's decision during a meeting at Khlong Prem Prison, Mr Narin said.
The former minister is serving 42 years after being convicted of involvement in fraudulent government-to-government rice sales when he was commerce minister in the administration led by then-prime minister Yingluck Shinawatra.
He was sentenced to prison on Aug 25.
Mr Narin said he will make another request for Boonsong's release on bail after he files the appeal.
His team were speeding up preparation of the appeal case. "We are not discouraged and will fight the case to the end," Mr Narin added.