Sonthiya submitted his letter via government spokesman Yongyuth Mayalarp at Government House. He said he wanted Thaksin to return to the Kingdom so he could take responsibility for what he did.

"Thaksin is a former prime minister, and he is Thai ... if he returns to country and is found guilty, the government can take legal action against him," said Sonthiya.

Sonthiya cited the example of ousted Iraqi dictator Saddam Hussein, who was recently sentenced to death after being found guilty of crimes against humanity.

Sonthiya said the government should also allow Thaksin to return so that the ousted PM could communicate directly with his party members and supporters.

"The government can make a deal with Thaksin and his former ministers to ban them from politics for five years," he said.

"If the government forces Thaksin to stay abroad, they won't be able to solve underlying problems, and martial law will not be lifted."