
The ruling came following a hearing on the legality of the emergency rule as per the petition by the defence of three red-shirt co-leaders in the police's custody.
The defence had pinned hope on the legality as the ground for temporary release of Veera Musigapong, Natthawut Saikua and Weng Tojirakan.
The defence argument was authorities had no justification to detain the three because the prime minister had failed to seek the Cabinet review within three days after the April 12 declaration of the state of emergency.
The court cited the testimony of Cabinet secretary general Surachai Phuprasert as evidence of the government's compliance on procedures for emergency rule.
Surachai said the prime minister had consulted six Cabinet members before imposing the state of emergency which tantamounted to the green light from the Cabinet.
He confirmed that the Cabinet had held a debate on April 17, the first formal meeting following the riots, and approved the state of emergency.