The 20, convicted on charges related to emergency rule violations, will be released tomorrow, Thida said.
The remaining red shirts, including 32 being remanded on politically-related charges, would soon be transferred to a special correctional facility being run separate from other prisons, she said.
The special facility, located near the police officers club, is undergoing renovation to serve as a detention centre.
The red shirt chairwoman said the red shirts would keep a close watch over the political development.
“The political situation is not stabilised,” she said, citing the legal proceedings to disqualify Pheu Thai MP Jatuporn Promphan as a sign of political disturbance.
She voiced suspicion that the attack on Jatuporn was a pretext to pave way for the dissolution of the Pheu Thai Party.
She said the party would win even a bigger election victory if faced with punishment by disbandment.
She vowed to spearhead the charter rewrite in order to cancel the coup-sponsored Constitution.