Don’t look now, but the ruling Partido Demokratio Pilipino (PDP) at the House of Representatives finds itself on shaky ground as Davao City Rep. Paolo Duterte is poised to take over the leadership of the National Unity Party (NUP) to fill the void created by the resignation of Capiz Second District Rep. Fredenil Castro.

Castro cited propriety in his decision to leave the NUP, further saying that he found it inappropriate to stay with the party after he went against its decision to back Taguig Rep. Alan Peter Cayetano who went on to win the speakership.

He admitted backing Leyte Rep. Martin Romualdez, who accepted Cayetano’s offer to become the House Majority Floor Leader for the whole three years left in President Rodrigo Duterte’s term.

The other candidate, Marinduque Rep. Lord Allan Velasco who is also a PDP stalwart, will have to wait 15 months before he assumes the speakership.

But Velasco’s turn, based on Cayetano’s so-called “Magellan formula” of 15 months for him and 21 months for Velasco, now seems in peril as 30 other PDP members are now also said to be leaving the President’s party.

The PDP exodus, reports said, was sparked by Cayetano’s distribution of committee posts.

The PDP was among those who supported Cayetano after Velasco had agreed to step aside and honor the term-sharing formula.

The mass PDP withdrawal will reduce the PDP to 65 from its the current 95 congressmen.

The NUP, meanwhile, will raise its membership to about 50 congressmen, gearing the party towards a possible power shift in the near future.

“I feel that I could no longer be effective as a member of the party, as president of the party, because I took the opposite direction during the speakership race,” Castro said.

The former House majority leader also said he “cannot associate” with lawmakers who “during the time that Alan Peter was not yet clear of winning as Speaker of the House, they were also campaigning against Cayetano. But after his election as Speaker, you see them there asking, requesting, pleading for a position or chairmanships.”

He also denied that his resignation was driven by fear of the President’s son replacing him as party leader.

“I did not even hear before my resignation that Congressman Duterte was entering the National Unity Party,” he said. He cited that there is a “50-50” chance the NUP can emerge as a major House power due to the recent developments.

“While it is true that Polong Duterte could be a member or is prospectively a member of the NUP, still PDP is the President’s political party,” he explained.

Castro said he is “inclined” to join Romualdez’s party, the Lakas-Christian Muslim Democrats (Lakas-CMD).

“I am still thinking whether my principle and my kind of politics would jive with Lakas,” he said.

However, he admitted that he would not have quit the NUP had Velasco won as speaker.

“The reason is simple. Lord Allan Velasco was not the candidate of the National Unity Party.

Therefore, there was absolutely no reason for me to be resigning considering that I did not take an inconsistent position with that of my political party,” Castro said.

Meanwhile, Deputy Speaker and NUP party stalwart Roberto Puno also on Monday revealed that the President’s son may take the NUP leadership.

“I think as much as possible, we’d like Paolo Duterte to take a position within the National Unity Party,” Puno said, noting that the NUP is set to meet on Tuesday at a hotel in Quezon City to elect their national officers.

Currently, there are 50 NUP members in the House of Representatives — an increase from the previous 25 after the 2019 elections.

Puno said they would like their membership to stay within that number.

“Internally, we have decided not too much more than 50, that should be a good enough number. Because beyond that, from experience, NUP has not wanted to go beyond that,” he said.

“In the 17th Congress, we ended the elections with 60 NUP members and even that was a little unwieldy already in the opinion of the party leadership,” he added.

Puno attributes the increase in their membership to their reputation of having “close-knit” members.

“We have shared principles and that we have common goals. I’d like to think that people look at our party and see that this is something that they’d like to join, and we have always taken a party position and deliver our party position,” he said.

As far as Puno is concerned, the transfer of some PDP members to NUP would not have much effect on the former’s hold as the biggest political party in the House of Representatives.

“For me, PDP remains as the ruling party. PDP remains as the party in Congress with the largest number of members. That won’t change and because it won’t change, then there’ll be no change in the party positions,” he stressed.