In a statement released yesterday, the group, which is campaigning against the political movement around Thaksin Shinawatra, said the government appeared to be tolerating continuing circumstances that could pose threats to the monarchy.
"The movement has been prevalent among the public and the media in the form of interviews, messages and images on websites, leaflets, magazines and CDs," the PAD said.
It said the current administration, which it called a "puppet government", was tolerant when certain Cabinet members extolled viewpoints "that are perilous to the monarchy".
"To allow people like this to stay in the Cabinet is a threat to the constitutional monarchy," the statement said.
The group issued its latest statement after a meeting of its five leaders - Chamlong Srimuang, Somsak Kosaisuk, Piphob Dhongchai, Somkiat Pongpaiboon and Sondhi Limthongkul, together with PAD coordinator Suriyasai Katasila.
The PAD said the government risked Thai sovereignty over disputed land adjacent to the Preah Vihear Temple if it allowed the Cambodian government to unilaterally seek World Heritage Site status for the area.
The PAD vowed to protect the monarchy and called on the government to deal with people acting in contempt of the highest authority. The statement also warned the government "not to create conditions for a coup".