"The political crisis is likely to return if the Council for National Security insists on having soldiers in control of state enterprises," Amorn Amornratananont said.

Amorn and his fellow campaigners Chumphol Sangthong and Wisanu Boonmarat are known for promoting the legacy of the three democracy uprisings of October 1973, October 1976 and May 1992.

The three men will ask the Stock Exchange of Thailand tomorrow to investigate whether military domination of state enterprise boards violates corporate-governance codes.

Many state enterprises have been privatised and listed on the stock exchange. Their directors receive eye-popping allowances.

The campaigners will on Tuesday petition for the prime minister to make the boards more well-rounded by putting representatives of minority shareholders, labour unions and consumers on them.

Amorn said the military's increased presence in state enterprises might be a sign that the coup-makers had succumbed to greed and temptation.

Former prime minister Chavalit Yongchaiyudh urged the coup-makers to make it clear to the public that they would not enrich themselves.

"I am speaking out with good intentions to remind younger officers not to veer off course after seizing power," he said, alluding to his military ties.

This was the second time that Chavalit has admonished the CNS. On Friday he said it should not push for control of state enterprises because soldiers were not trained to run businesses.

Democrat Party spokesman Ong-art Klampaiboon said time would tell if the participation of senior military men would really benefit state enterprises.

"These senior officers will have to prove themselves," he said, reminding them that they were under close scrutiny by society as their military predecessors had failed to improve state-enterprise performance.