MANILA, Philippines -- Those aspiring to replace President Gloria Macapagal-Arroyo are the greatest threat to national security because of their capability for "destabilization," Deputy National Security Adviser Luis “Chavit” Singson.

At the same time, Singson fired back at criticism of his appointment, saying he is qualified for the job, having served in local government for years.

"Ang most pressing security threat, yung mga kababayan natin na nagmamadaling maging presidente. Gusto nilang manggulo. [The most pressing security threat is our countrymen who are in a hurry to be president. They want to stir up trouble]," Singson said in a phone interview from Vigan City.

"Yung destabilization na ginagawa nila, kawawa naman ang maliliit na tao. Kailangan tumulong na lang sila [The destabilization that they're doing, it's the poor people that suffer. They should help, instead]," he said.

Singson declined to name the presidential aspirants whom he considered threats to national security, but said: "Alam nyo na yun, yung kaibigan ko, yung salita nang salita [You know the person, my friend who keeps on talking]."

Among those who criticized Singson's appointment was former president Joseph Estrada, who has hinted that he would run for president in 2010 if the political opposition fails to field a single candidate.

Singson's expose of Estrada's alleged kickbacks from the illegal numbers game "jueteng" in late 2000 led to the former president’s downfall in early 2001, to be replaced by his then vice president, Gloria Macapagal-Arroyo.

Soon after Estrada’s conviction in September 2007, he was pardoned and ordered released by Arroyo.

Singson lost in the May 2007 senatorial elections, in which he ran under the administration's Team UNITY ticket.

The former Ilocos Sur governor cited his stints as chairman of the league of provinces, and as local police chief.

"Sanay tayo sa problema [We're used to problems]," he said. "We [Ilocos Sur] used to be the most notorious province, now it's peaceful."

But Singson was evasive when asked about the conflict in Mindanao, saying: "I will meet with [National Security Adviser] Secretary Gonzales on that."

When asked about communist insurgents, Singson said he could talk to exiled Communist Party of the Philippines (CPP) spokesman Jose Ma. Sison since he is from Ilocos Sur

"Si Joma Sison, taga Ilocos Sur yan, pwede ko siyang kausapin [Joma Sison is from Ilocos Sur, Ian talk to him].," Singson said.

In Malacañang, deputy presidential spokesperson Anthony Golez defended Singson's appointment.

"He has been a local government leader for three decades. His expertise was rooted from fact he was chief of police. The fact that he lost election nobody can negate milestone he has done for his province," Golez told reporters.

Golez added that Singson was "built" for the job because of his capability to process and analyze intelligence reports.