Suriyasai voiced concern over press reports that Thaksin planned to return in December following rising fears of political "undercurrents" against the Council for National Security (CNS) and its interim government.

He said Thaksin had only sent letters to the Thai Rak Thai Party about his plans, and should clarify when he plans to return.

"Thaksin should make it clear so that the country can move on without having to worry about political undercurrents," he said.

Suriyasai said Thaksin should be allowed to come back to defend himself against corruption allegations, especially over the land purchase by his wife, Khunying Pojaman Shinawatra.

"We disagree with him coming back before he is formally charged with any wrongdoing or immediately returns after the martial law is lifted," he said.

CPD adviser Piphop Dhongchai called on the CNS to be bold and prove whether Thaksin is guilty of the charges it cited when overthrowing him.

"Thaksin is a very powerful politician. He believes that he is right and has not committed any wrongdoing," he said. "Using the legal process in a bureaucratic system is not enough to incriminate Thaksin; the CNS has to wield its power. If it used it to seize power, it must be bold enough to bring out the truth."