Thai Prime Minister Yingluck Shinawatra, before departing Bangkok for a meeting in Cambodia on Friday, called on all parties to stay calm and accept the Constitution Court's verdict on the constitutionality of the charter amendment bill.

Asking the public not to resort to violence and act within legal limits, she said the government is duty-bound to continue working and asked all parties including the red shirts to wait for the court decision.

"Any move should be within the legal framework. Don't resort to any violence. Eventually, (I) believe all sides should be able to talk to each other as we are all Thais," she added.

The Constitution Court is scheduled to deliver its verdict around 3 p.m. local time. The judges will rule whether the bill to amend Section 291 of the Constitution contravenes Section 68.

The opposition claimed the ruling Pheu Thai Party's move to amend Article 291 to set up a drafting committee is tantamount to an attempt to topple the constitutional monarchy.

The Metropolitan Police Bureau deployed three companies of police to provide security and to keep order at the Constitution Court. Police reinforcements are possible depending on the situation. Deputy Prime Minister Gen Yuthasak Sasiprapa said the military is ready to reinforce police to cope with situation after the court ruling.