Lt Gen Paradorn said he based his opinion on the fact that the PDRC planned to shut down all government offices in the South next week to set a precedent for its supporters in other regions to follow.
Moreover, it was believed the PDRC would step up activities to obstruct the nationwide advance voting scheduled for Jan 26.
Therefore, the authorities are required to step up intelligence operations and take stricter measures to protect the people and prevent untoward incidents.
At the same time, the government would have to intensify its public relations for the people to be aware of possible impacts from the protests, he said.
Concerning the shooting of a PDRC guard at the Lat Phrao intersection late Saturday night, Lt Gen Paradorn said the authorities had conducted an in-depth investigation and could affirm that it was not from the kind of weapon that is usually used by snipers but from an ordinary firearm.
According to government intelligence, the Lat Phrao intersection has become one spot for the most risky violent incidents because it is a densely-populated area where some people might not be satisfied with the PDRC protests, not to mention third parties wanting to create a violent situation and put the blame on the government, the NSC chief said.
Lt Gen Paradorn said the government would try to prevent confrontations between groups supporting the election and those opposed to it. He said groups supporting the election, in particular, had stepped up their activities.
The NSC chief said the government would continue to use the Internal Security Act to handle the situation. But if the situation turned more violent and looked to be getting beyond control, the government might consider invoking the executive decree for the administration of the country in an emergency situation, or the emergency decree, he added.
Lt Gen Paradorn was giving an interview before attending a meeting of the Centre for the Administration of Peace and Order (Capo), chaired by Deputy Prime Minister Surapong Tovichakchaikul, at the Office of the Defence Permanent Secretary.
Those attending the meeting included caretaker deputy prime ministers Niwatthamrong Boonsongpaisarn and Pongthep Thepkanchana and caretaker Information and Communication Technology Minister Anudit Nakornthap.
Itt was reported that caretaker Prime Minister Yingluck Shinawatra did not turn up for the meeting, which is held daily to assess the protest situation.