MANILA - Senator Panfilo Lacson on Tuesday urged the Office of the Ombudsman to look into billions of alleged insertions in the 2019 national budget.

Lacson earlier said House Speaker Gloria Macapagal Arroyo's district in Pampanga will receive P2.4 billion worth of projects while a Camarines Sur representative is set to have P1.9 billion worth of projects.

"Exposé pa more! A single contractor bagging 30 flood control projects worth billions of pesos calls for a congressional inquiry/Ombudsman investigation. Thank God I found an unlikely 'ally' in Cong. Andaya," Lacson said in a post on his Twitter account.

The senator was referring to House Majority Leader Rolando Andaya, who earlier said that a single contractor from Bulacan cornered infrastructure contracts in Bicol, even if it was not qualified for the job.

• READ: House foiled a pork barrel scam 'in the making' - Andaya

"With exposés on 'pork' in the proposed P3.7-trillion budget for 2019 now coming out left and right, it may be time for new Ombudsman Samuel Martires to step into the picture," Lacson said in a statement.

"Both the House of Representatives and the Office of the Ombudsman can conduct their own probes into the revelations," he said.

• Pampanga, Camarines Sur top list of congressional insertions: Lacson

Opposition senators backed Lacson's crusade against unlawful insertions in the budget.

The Department of Public Works and Highways would be thoroughly questioned on the Senate floor to shed light on the issue, Senate Minority Leader Franklin Drilon said.

In 2013, the Supreme Court declared legislative discretionary funds unconstitutional. Still, senators continue to receive a P200-million allocation in the annual budget, while House members are each given a P60-million fund for their projects.