While stressing that the present stand-off should be tackled through political means, Gen Somjet Boonthanom, the chief adviser to the defence permanent secretary's office, said military intervention may be necessary if all other means failed.
''If the problems cannot be resolved by democratic means and the country is caught in a deadlock, a coup may be necessary,'' said Gen Somjet, a close aide to former Council for National Security (CNS) secretary-general Winai Phattiyakul.
He urged parties involved in the dispute not to focus on winning and suggested the government consider its future if it is unable to steer the country away from political turmoil.
In his national broadcast yesterday, Mr Samak said again that he would stay on as prime minister, to defend democracy and the monarchy.
He also dismissed the possibility of the military mounting a coup to topple his administration when he attends the United Nations General Assembly session in
Former prime minister Thaksin Shinawatra was ousted in 2006 while he was at a UN function.
''I will deliver my speech at the United Nations and I don't believe any unwanted incidents will happen, such as when Mr Thaksin went to speak there.
''The military knows the international community will not tolerate [another] coup,'' he said.
PAD core member Chamlong Srimuang said his group would not negotiate as long as Mr Samak stayed in power.
Senate Speaker Prasopsuk Boondej, assigned by parliament to mediate the conflict, had yet to contact the PAD, he said.
Mr Prasopsuk said he will discuss the PAD's conditions with his working team today.
The mediation attempt comes after Mr Samak imposed a state of emergency in the wake of a violent clash between pro- and anti-government demonstrators last Tuesday.
Political parties will today also explore possible options to mitigate the conflict. Party leaders and secretaries-general are expected to attend.
Meanwhile, a source in the People Power party said Mr Samak is likely to dissolve the House of Representatives eventually. It was only a question of when.
The source said if cabinet endorses the annual reshuffle of state officials at the mobile cabinet meeting tomorrow, the chances of a House dissolution are high.
Some even expect the announcement on Saturday, said the source.
''Mr Samak and his group are buying time to prepare for elections,'' said the source.