MANILA (UPDATE 2) -- Senator Francis Pangilinan said Tuesday he resigned as president of the Liberal Party, taking responsibility for the apparent loss of all opposition senatorial candidates.

Pangilinan tendered his resignation to Vice President Leni Robredo, the chairperson of the LP.

"As campaign manager for the Otso Diretso slate, I was unable to ensure our victory in the elections and I therefore assume full responsibility for the outcome and hold myself primarily accountable for this defeat,” he said in a statement.

Quezon City 6th District Rep. Kit Belmonte also resigned as LP secretary general, sources said.

Nine senatorial candidates backed by President Rodrigo Duterte's PDP-Laban and his daughter, Davao City Mayor Sara Duterte-Carpio's Hugpong ng Pagbabago, are set to be proclaimed. The three other winning candidates are independents.

Otso Diretso's slate included incumbent Sen. Bam Aquino and former Sen. Mar Roxas.

One source told ABS-CBN News that Pangilinan was most distraught over the failure of Aquino to secure a second 6-year term.

Another source said the resignations were due to "command responsibility."

Robredo rejected Pangilinan and Belmonte's resignation letters, saying the party would address the work that needs to be done "together."

• Robredo rejects Pangilinan resignation as LP president

NO CLAMOR VS KIKO

"There was no clamor for Sen Kiko’s resignation," Liberal Party vice president for external affairs Erin Tañada told ABS-CBN News.

Tañada was also part of the LP-backed Otso Diretso slate that was shut out from the senatorial race’s “Magic 12.”

"His resignation is not a message that he is abandoning the Liberal Party. His resignation is a sign of humility, taking responsibility for what has happened," Tañada said.

"I admire the courage he showed by taking the challenge in leading and managing the Otso Diretso slate despite the obvious lack of resources and the attacks by the President on the opposition ticket," he said.

No one from the party blamed Pangilinan and Belmonte for the loss, party stalwart and Caloocan Rep. Edgar Erice told ABS-CBN News in a separate interview.

"I don't think anybody would suggest na tanggapin 'yan kasi naniniwala naman kami na nagperform sila," Erice said.

"It's just malakas lang talaga yung kalaban," he said.

'WAKE UP CALL'

The LP's loss was "a wake up call to the party itself," Tañada said.

"Maybe it's time to restudy how we would attract new blood and new members and make the members play a very important role in playing party decisions," he said.

The LP only has 3 members in the Senate: Pangilinan, Senate Minority Leader Franklin Drilon, and Sen. Leila de Lima, who is detained. Akbayan Sen. Risa Hontiveros remains an ally.

In the House of Representatives, the Liberals landed 18 congressional seats.

• Liberal Party clout dwindles with only 30 top local poll victories

The Liberals would have to wait for "the right time" instead of trying to recruit more members, Erice said.

"I don't think that anybody in congress would want to join LP at this time," he said noting that the same "decimation" happened with Lakas after President Gloria Macapagal Arroyo fell from power in 2010.

"'Yung mga natitira [sa LP] 'yun 'yung matitibay na naniniwala sa prinsipyo ng partido. I would rather wait for the right time and we'd just exercise our task to provide check and balance," he said.

The Liberal Party has a meeting next week to discuss how the party would move forward, Erice said.

"Hindi pa nga kami naga-assess, we're still moving on from the loss. Pinagpapahinga pa kami," Erice said.

"Parang decimated na kami masyado, wala na ata kami ibaba pa so will just continue with what we have," he said.