In the May 1998 presidential election, it aligned itself with other political parties to form the Laban ng Makabayang Masang Pilipino (Struggle of the Patriotic Filipino Masses).

It was then that the PMP was accredited as a political party with the objective of helping to uplift the lives of the Filipino people, especially the poor and the disadvantaged, through effective and efficient social and economic reforms.

Estrada overwhelmingly won the vice-presidency, defeating former Chief Justice Marcelo Fernan of the Laban ng Demokratikong Pilipino along with five other candidates.

PMP played a lead role in the establishment of the opposition coalition Laban ng Makabayang Masang Pilipino (LAMMP), which also counted among its members the LDP and NPC.

Estrada won the presidential election, garnering almost 11 million votes and defeating nine other candidates including House Speaker Jose de Venecia Jr. of Lakas–NUCD–UMDP.

Poe and Legarda lost the election to incumbent President Gloria Macapagal Arroyo and Senator Noli de Castro.

On January 18, 2008, Joseph Estrada's Partido ng Masang Pilipino (PMP) placed full-page advertisements in Metro Manila newspapers, blaming EDSA 2 of having "inflicted a dent on Philippine democracy".