The Party-List System Act, or Republic Act No. 7941, provides for the election of party-list representatives.
Enacted in March 1995, the law enables “Filipino citizens belonging to the marginalized and underrepresented sectors, organizations and parties… to become members of the House of Representatives.”
The act defines the party-list system as a “mechanism of proportional representation.” Section 11 of the law says party-list representatives “shall constitute twenty percentum of the total number of the members of the House of Representatives, including those under the party-list.” This provision enables Article VI, Section 5, of the 1987 Constitution.
The law authorizes the Commission on Elections (Comelec) to tally all votes cast for party-list groups nationwide then rank these groups according to the number of votes they polled.
It entitles each party to a maximum of three seats.
In April 2009, the Supreme Court introduced the Carpio formula for the computation of the winners for party-list seats in the House.
Under the previous formula, a party-list group must win at least 2 percent of all the votes cast in the party-list election to be eligible for a seat in the House.
Voting unanimously, the Supreme Court declared the 2-percent threshold unconstitutional, and gave a seat to a party-list group that won less than 2 percent of the votes, and one or more additional seats to a group that polled more than 2 percent.
The Supreme Court ruled, however, that the total number of party-list representatives must remain at 20 percent of the total number of seats in the House as prescribed by the Constitution.
Fifty-eight party-list seats are at stake in the 2013 elections. Inquirer Research
Source: comelec.gov.ph, 1987 Constitution, lawphil.net, Inquirer Archives