Manila: Philippine Vice President Jejomar Binay started strengthening his political party by forming coalition with other groups to help field candidates in the 2013 congressional elections, and to prepare for his presidential candidacy in 2016, sources said.

Several other parties have agreed to beef up the congressional slate of the vice president's newly formed United Alliance Party, political analyst Prospero de Vera said.

Binay's party initially received the support of the former ruling Lakas-Christian Muslim Democrats (Lakas-CMD), which was headed by former president Gloria Arroyo, said de Vera.

Before the 2010 elections, however, Arroyo who then ran for a seat at the House of Representatives gave up Lakas leadership in favour of her party's presidential candidate Gilberto Teodoro. He is the second cousin of President Benigno Aquino. It is not yet known if Teodoro will run for senate in 2013.

Meanwhile, Senator Ramon "Bong" Revilla Jr., current president of Lakas, confirmed that his party has joined Binay's new party, to help Lakas field its own senatorial candidates.

At the same time, several other senators who are running again in 2013 have agreed to run under Binay's party. They are Senators Aquilino "Koko" Pimentel, Gregorio "Gringo" Honasan, Francis "Chiz" Escudero, and Loren Legarda.

Also included in the senatorial candidates of the vice president's party are former Senators Ernesto Maceda, Jose Miguel Zubiri, and Richard Gordon; Congressman Jack Enrile and Mayor Jose Victor "JV" Ejercito (son of former president Joseph Estrada).

The victory of Binay's senatorial candidates in 2013 could help the vice president strengthen his grip in the presidential elections in 2016, explained de Vera.

The presidential candidate to be fielded by the Liberal Party of President Aquino is not yet known.