Sonthi said demonstrations on Saturday had no sting - they argued the "same old topics".

He said the government would consider legal action against the public disclosure by protest leaders of a private conversation alleged to involve Privy Council President Prem Tinsulanonda. They could be charged with contempt of court.

"I was told that you cannot make sense of what was on the tape," he said.

First Army Region commander Lt-General Prayuth Chan-ocha believed Thaksin supporters had lost public support. The public dislikes political turmoil, he said.

He believed provincial residents would not join protesters in the capital. State officials have reached an understanding with them, he added.