But a pro-red Australian man Conor Purcell has pleaded not guilty.
A Briton linked to the red shirts on Thursday changed his plea to guilty of violating the emergency rule, paving the way for his release.
Jefferey Savage would be freed today as he has already served out his one-and-half month term during remand. He is subject to deportation after being freed.
Following his admission of guilt, the Pathum Wan Court convicted Savage and sentenced him to serve three months in jail.
His jail term was cut in half, equivalent to time served in remand, because of his guilty plea as ground for leniency.
The magistrate court then ordered his release pending the arrangements for deportation.
Savage's charges stemmed from his involvement in the redshirt rally from March 14 to May 19.
In a separate case, Australian man Conor Purcell has pleaded not guilty to violating the emergency rule. His trial will start on September 5.