The coup at the House of Representatives on Monday may serve as the strongest argument against a shift to a parliamentary form of government, Sen. Panfilo Lacson said Tuesday.

Lacson also said that if former President Gloria Arroyo’s ascension to the speakership is a prelude to becoming Prime Minister, the Senate is there to defend and assert its role under the 1987 Constitution.

“Regardless of whether it was Rep. Arroyo or somebody else replacing the ousted Speaker, what happened yesterday is a strong argument against a parliamentary form of government where patronage politics plays a major, if not the only, role in selecting our country’s top leader,” he said.

He added that if Arroyo’s taking the speakership from Pantaleon Alvarez is part of a plan to make her Prime Minister, those behind her “better think twice.”

Lacson said the Senate, both majority and minority blocs, had agreed to close ranks to defend the Senate’s role in revising the Constitution.

“If GMA’s ascension to the speakership is a prelude to becoming Prime Minister, they better think twice because the Senate, both majority and minority have agreed to close ranks to defend and assert our role under the 1987 Constitution in revising or amending the same. That, I can say with certainty and conviction,” he said.

Lacson also reiterated the coup in the House was “awkward, ugly, low and disgraceful” due to the timing and manner it was carried out.

“In a manner of speaking, even the traditionally symbolic mace was in a maze yesterday at the Batasan, not knowing whose authority it would represent between the two contending personalities,” he said.