MANILA, Philippines -- Senator Miriam Defensor-Santiago has replaced Executive Secretary Eduardo Ermita as head of the technical working group (TWG) on the controversial baselines bill after some opposition senators raised questions about the Palace official heading the body.

Detained Senator Antonio Trillanes IV filed a resolution last week seeking an investigation into the constitutionality, legality and propriety of Ermita’s presiding over a TWG meeting in Malacañang.

Senate Minority Leader Aquilino Pimentel Jr. has backed Trillanes’ position.

Santiago said the committee on foreign affairs, which she chairs, will vote on Trillanes’ resolution upon receiving both memoranda.

“This is the first time that a senator has ever questioned the discretion of a committee chair to appoint the head of a TWG and the first time a senator has ever questioned the credentials of the head of the technical working group,” she said.

“Normally, we don’t even take notice of who are the members of the TWG. We just assign that to our chief of staff,” she pointed out.

Nevertheless, Santiago said she was appointing her deputy chief of staff, Fatima Panontongan, to head the TWG while waiting for Trillanes and Ermita to give their positions on the issue.

“I have appointed my deputy chief of staff as chair so that the technical working group can continue to hold meetings without delay since we’re already concerned that our baselines bill might get too delayed for filing by May 2009,” she told reporters.

In a letter to Trillanes on Monday, Santiago requested her detained colleague to cite the legal basis of his charges against Ermita within 15 days. She also requested Ermita to comment on the matter within the same period.