By Audrey Morallo (philstar.com) | Updated October 6, 2017 - 3:25pm

MANILA, Philippines — Senate President Aquilino "Koko" Pimentel III on Friday announced six potential senatorial candidates of the administration Partido Demokratiko Pilipino- Lakas ng Bayan for the 2019 midterm elections.

Pimentel, who is the president of PDP-Laban, said that half of the party's 12 candidates for the senatorial elections could include himself, House Majority Leader Rodolfo Fariñas (Ilocos Norte), presidential adviser Francis Tolentino, Rep. Karlo Nograles (Davao City), Rep. Geraldine Roman (Bataan) and Rep. Alfredo Abelardo Benitez (Negros Occidental).

Pimentel however was quick to emphasize that the list is not yet final and official as the matter is still "developing, evolving."

The senate president said that the administration party would try to field 12 candidates but is also open to entering coalitions with other parties to complete its slate.

"If we cannot come up with 12, then we are open to entering into coalition agreements with other parties. This is a 'developing/evolving' matter hence not final not official; just my personal preferences,” Pimentel said in a text message to reporters.

Before joining PDP-Laban, Roman, Benitez and Fariñas were members of the Liberal Party, the administration party from 2010 to 2016.

Tolentino, Aquino's Metropolitan Manila Development Authority chairman, was supposed to run under the LP slate in the 2016 elections but was dropped after being involved in a controversy involving a lascivious dance performance by an all-girl group.

The former MMDA chief has a pending poll protest against Sen. Leila De Lima, who placed 12th in last year's senate elections.

Tolentino, who got 1.3 million votes fewer than De Lima, asked the Senate Electoral Tribunal to remove the detained senator allegedly for committing fraud.

Roman is part of a political family in Bataan and is the first transgender to be elected to Congress.

Pimentel is expected to face a legal problem in his bid for reelection as the 1987 Constitution allows only two consecutive six-year terms for senators.

The senate president served a little less than two years of his first term as he was locked in an electoral protest against Juan Miguel Zubiri, whom he accused of fraud in the 2007 elections.

Zubiri denied cheating but resigned from the Senate before the Senate Electoral Tribunal could decide on the protest. Pimentel took his oath of office as senator in August 2011.

Pimentel ran for a second term in the 2013 eelctions and won.