PMA started as a broad alliance of automotive, iron and steel, and electronics and electrical sectors.
PMA was launched on November 9, 2003 after a series of consultations that started in 2002.
Seeing the need for a legal identity, PMA registered to the Department of Labor and Employment (DOLE) as a workers’ association on March 14, 2005. This reinforced the Alliance’s work of consolidating organized and unorganized workers in the metal industry.
On May 13, 2008, PMA registered to the DOLE as a National Union to serve more workers by maximizing the coverage of Republic Act 9481 or the Act Strengthening the Workers’ Constitutional Right to Self-Organization, enacted on May 25, 2007.