Former Senate President and Liberal Party (LP) senatorial candidate Frank Drilon said Monday Deputy Presidential Spokesperson Gary Olivar must immediately renounce his American citizenship or quit his Malacañang job.

Otherwise, Drilon said, both Olivar and the Office of the President, the appointing authority, are guilty of violating the provisions of Republic Act 9225 or the Dual Citizenship Law.

Drilon, the principal author of RA 9225, said Olivar cannot continue serving as Malacañang deputy spokesperson and hold on to his US citizenship since Section 5 of the Dual Citizenship Law prohibits such tenure in the government.

He said during a meeting with Manila Bulletin editors that the law clearly provides that a dual citizen who accepts an appointive or elective position in the Philippine government must first renounce his foreign citizenship before assuming office.

“Gary Olivar cannot have his cake and eat it too,’’ Drilon said. “He must proceed to the US Embassy on Roxas Boulevard and renounce his US citizenship. If he cannot do that, then he has no choice but to immediately resign as deputy presidential spokesperson.’’

“I should know. I wrote the Dual Citizenship law as a member of the 12th Congress,’’ Drilon said.

On Wednesday last week, Malacañang assured the public that Olivar was a Filipino citizen even as it admitted that he was also a citizen of the United States.

Executive Secretary Eduardo Ermita explained that Olivar was a holder of dual Filipino and US citizenships.

He claimed that under RA 9225, Olivar does not need to renounce his foreign citizenship to be considered a Filipino citizen.

Drilon explained that the law was crafted precisely to avoid conflicts of interest. He said that in the unlikely event that the Philippines and the US go to war against each other, Olivar’s loyalty would be put into serious question.