Brief history and mandate

Representatives for the youth and labor sectors were first elected to the legislature in the time of the late dictator Ferdinand Marcos who installed a unicameral system that was abolished following his ouster.

After the 1986 People Power Revolution and the return to a bicameral Congress, sectoral representatives remained in the House but were appointed by the president from 1987 to 1998.

The party-list system is intended to democratize political power by giving political parties that cannot win in legislative district elections a chance to win seats in the House of Representatives. The 1987 Constitution mandates that party-list representatives shall constitute 20% of all seats in the House of Representatives.

On May 11, 1998, the first election for party-list representation was held simultaneously with the national elections. According to Comelec’s rules then, groups that received 2% of the total party-list votes earned one party-list seat in Congress, with additional seats for every 2% thereafter.

However, the Supreme Court has twice changed the formula for determining winning party-list groups: first in 2000 and then in 2009.

The high court has also gone back and forth on what constitutes a party-list group, originally ruling in 2001 that only those from the marginalized and underrepresented sectors could participate in the system but reversing this in 2013, deciding that organizations “do not need to organize along sectoral lines and do not need to represent ‘any marginalized and underrepresented’ sector.”

In its 2013 ruling Atong Paglaum, Inc. vs. Comelec, the Supreme Court laid down the parameters currently used for party-list elections:

• Three different groups may participate in the party-list system: (a) national parties or organizations, (b) regional parties or organizations, and (c) sectoral parties or organizations
• National parties or organizations and regional parties or organizations do not need to organize along sectoral lines and do not need to represent any "marginalized and underrepresented" sector
• Political parties can participate in party-list elections provided they register under the party-list system and do not field candidates in legislative district elections. A political party, whether major or not, that fields candidates in legislative district elections can participate in party-list elections only through its sectoral wing that can separately register under the party-list system. The sectoral wing is by itself an independent sectoral party and is linked to a political party through a coalition.
• Sectoral parties or organizations may either be "marginalized and underrepresented" or lacking in "well-defined political constituencies." It is enough that their principal advocacy pertains to the special interest and concerns of their sector. The sectors that are "marginalized and underrepresented" include labor, peasant, fisherfolk, urban poor, indigenous cultural communities, handicapped, veterans, and overseas workers. The sectors that lack "well-defined political constituencies" include professionals, the elderly, women, and the youth.
• A majority of the members of sectoral parties or organizations that represent the "marginalized and underrepresented" must belong to the "marginalized and underrepresented" sector they represent. Similarly, a majority of the members of sectoral parties or organizations that lack "well-defined political constituencies" must belong to the sector they represent. The nominees of sectoral parties or organizations that represent the "marginalized and underrepresented," or that represent those who lack "well-defined political constituencies," either must belong to their respective sectors or must have a track record of advocacy for their respective sectors. The nominees of national and regional parties or organizations must be bonafide members of such parties or organizations.
• National, regional, and sectoral parties or organizations shall not be disqualified if some of their nominees are disqualified, provided that they have at least one nominee who remains qualified.

Computation of number of seats of party-list groups

• The party-list representatives shall constitute 20% of the total number of representatives including those under the party-list.
• The allocation of seats under the procedure in the 2009 Banat ruling is as follows:
  (a) The party-list groups are ranked from the highest to the lowest based on votes garnered.
  (b) The party-list groups garnering at least 2% of the total votes cast for the party-list system shall be entitled to one guaranteed seat each.
  (c) Those garnering a sufficient number of votes, according to the ranking, shall be entitled to additional seats in proportion to their total number of votes until all additional seats are allocated. The percentage is multiplied by the remaining available seats (difference between the maximum reserved seats under the party-list system and the guaranteed seats to the two percenters). The whole integer of the product of the percentage and of the remaining available seats corresponds to a party’s share in the remaining available seats.
  (d) One seat to each of the parties next in rank shall be assigned until all available seats are completely distributed.
  (e) A three-seat cap is imposed such that a party-list cannot hold more than three seats.