PAD calls on army to 'subdue' govt

"When the government commits treason, it's the duty of the First Army Region, which has jurisdiction over the capital, to enforce martial law. They have the personnel and equipment to solve the problem completely," Chaiwat said.

"The Army is considered a state mechanism. But when the government is believed to have committed treason, the Army has to review its role and take action against the government," he said.

As the secretary-general of the People's Assembly of Thailand, Chaiwat submitted his open letter to Lt-General Kanit Sapithak, chief of the First Army, in which he accused the government and coalition MPs of exercising political power in the interest of a single person and themselves, instead of the public.

Their actions were a threat to the constitutional monarchy and a deviation from the spirit of the Constitution, he said.

Those people have set up a private army and encouraged the use of war weapons, which is a threat to national security, he said.

The appeal was not to ask the Army to take sides, but rather for it to perform its constitutional duty, he said.

Another open letter would be submitted after 10 days, he said, adding that in the meantime he would collect signatures from members of the public who agree with his move.

The PAD also said it would arrange activities to observe the funeral of HRH Princess Galyani Vadhana from today to Sunday.

There would be no political speeches at the PAD's rally site at Government House, which has been seized by PAD supporters for more than two months, said Pipob Dhongchai, a core PAD leader. Stage activities would focus on the Princess' life and contributions, he said.

The PAD began clearing Rajdamnoen Nok Avenue at 6am, after blockading the stretch between Makkhawan and Misakawan intersections as part of its protest.