An electoral official tallies the vote count at a polling station in Bangkok on 24 March, 2019 after polls closed in Thailand's general election. There have been talks to change Thailand’s current mixed-member apportionment (MMA) electoral system. (Photo: Chalinee THIRASUPA/ AFP)

An electoral official tallies the vote count at a polling station in Bangkok on 24 March, 2019 after polls closed in Thailand's general election. There have been talks to change Thailand’s current mixed-member apportionment (MMA) electoral system. (Photo: Chalinee THIRASUPA/ AFP)

Next Thai Election, Next Thai Electoral System?


The main ruling party and opposition parties want to change the electoral system to their advantage before the next election.

Since 1932, Thailand has had 20 constitutions (the most in Asia over this period), and many different electoral systems. While moves for a new constitution before the next national election have faltered, the fight over a new electoral system between the main ruling party and the opposition is heating up. 

The many past electoral systems have sought to reduce electoral malpractice, vote-buying, the prevalence of party factions, the fragility of coalition governments, and weak parties. Although electoral reforms have preceded almost every election, especially since 1997, they have not solved these problems. 

In the 2019 election, Thai voters again had to learn a new electoral system for the House of Representatives called a “mixed-member apportionment” (MMA) system with the stated goal of making every vote count. Under this system, the 500-member House of Representatives would have 350 single-member district and 150 party-list seats. Only parties that had reached the threshold of 71,065 votes should have been eligible for party-list seats.

Although the pro-military drafters of the 2017 Constitution claimed that the MMA system would lead to transparent electoral outcomes, the results demonstrated that the new rules favoured the pro-military party, Phalang Pracharat (PPRP). In response, parties that ended up on the opposition benches began to lobby to replace the MMA system.

The MMA system’s first run alerted politicians and academics to its “make every vote count” challenges. These include:

  • The single ballot system for both district and party-list contests favours candidates over political parties. Voters cast a single, fused ballot for a candidate instead of as in previous elections when they selected a candidate for their district and a party for the party-list seats. Under the current single ballot system voters may think their single vote is predominantly a vote for a candidate not their party. Candidates would be encouraged to conduct campaigns promoting themselves and leaving aside party policy; 
  • The complex post-voting seat distribution calculations allowed eleven very small parties with vote tallies lower than the 71,065 vote threshold to be allocated party-list seats. These fortunate parties later joined the pro-military ruling coalition – a development that handicapped the anti-military opposition in parliament; 
  • MMA favours new parties with a weak political base at the district level and hinders large parties in the party-list contest as it caps the total number of seats that a party can gain based on its share of total votes cast nationwide. As a result, Phuea Thai (PT), a major opposition party, was not allocated any party-list seats as the number of constituency seats PT won, 136, exceeded its total capped number of constituency and party-list seats. PPRP ended up with 115 seats (97 district seats and 18 party-list seats) to place second in the 2019 election and to compete successfully against PT to set up a coalition government.

Despite being seen as a beneficiary of the MMA single ballot system in 2019, many in PPRP think they can do better under a version of the double ballot system in the 1997 Constitution. Hence, on May 22, 2021, the next parliamentary sitting day, both ruling and opposition parties will submit a motion for section-by-section charter amendments to revise the electoral system and return to a double ballot system.

Phaiboon Nititawan, a PPRP deputy leader, states that the party will propose a mixed double ballot system with proportional representation (with a one percent of the total vote threshold) for party-list seats and a first-past-the-post plurality system for single-member districts. PPRP should benefit from this as it has developed its political base at the district level and attracted a large number of prominent politicians from other parties. PPRP should win a large number of district and party-list seats under this type of electoral system as the victorious Thai Rak Thai Party did in 2001 and 2005.                  

Opposition party electoral system reform efforts are being led by Move Forward Party, the successor to the Future Forward Party that shockingly won 80 seats in 2019 (50 party-list and 30 district seats), the third largest yield in this election. They propose a mixed-member proportional representation (MMP) system with two votes; one for a candidate in their single-seat electoral district, and one party-list vote. This system will use a seat allocation calculation process related to the one in the 2017 constitution. Candidates will win district seats based on the majoritarian rules by district. The party-list results will then determine how many total seats should be allocated to each party. Once that number is determined, the number of district seats awarded to each party will be deducted and the remainder allocated from the party-list seats. By using this system, these parties will potentially gain district and party-list seats.   

As the PPRP-led coalition controls the House, its proposal looks the most likely to prosper. If PPRP’s proposed electoral system is implemented in the next election, PPRP should win in a landslide. PPRP benefitted from the current electoral system, and may do so even more from the next one.


Punchada Sirivunnabood was Visiting Fellow at ISEAS – Yusof Ishak Institute. She is an Associate Professor in the Faculty of Social Sciences and Humanities at Mahidol University in Bangkok, Thailand.