Electoral system family

1997 Constitution attached, Articles 98-100 and 102

Article 98.

The House of Representatives consists of five hundred members, one hundred of whom are from the election on a party-list basis under section 99 and four hundred of whom are from the election on a constituency basis under section 102.

In the case where the office of a member of the House of Representatives becomes vacant for any reason and an election of a member of the House of Representatives has not been held to fill the vacancy, the House of Representatives shall consist of the existing members of the House.

Article 99.

In an election of members of the House of Representatives on a party-list basis, a voter shall have the right to cast ballot from the lists of candidates prepared by political parties; provided that only one party-list may be voted for and the territory of Thailand shall be regarded as the whole constituency.

The party-lists of candidates in the election under paragraph one shall be prepared by political parties. Each party shall prepare one list which shall contain not more than one hundred persons and be submitted to the Election Commission before the date an application for candidacy in an election on the constituency basis commences.

Names of persons in the party-list under paragraph one shall:

(1) consist of the names of candidates from equitably various regions;

(2) not be repeated by the names in the lists prepared by other political parties and names of candidates in the election on the constituency basis under section 102 and;

(3) be placed in numerical order.

Article 100.

The list of any political party receiving votes of less than five percent of the total number of votes throughout the country shall be regarded as one for which no person listed therein is elected and such votes shall not be reckoned in the determination of the proportional number of the members of the House of Representatives under paragraph two.
The determination of the proportion of votes received by the party-
list of each political party according to which the persons whose names are listed therein shall be regarded as being elected in that proportion shall be in accordance with rules, procedure and conditions provided by the organic law on the election of members of the House of Representatives and senators.

It shall be deemed that the candidates whose names are in the list of each political party are elected in respective order of the allocated numbers in the list in accordance with such proportional number of the members of the House of Representatives as determined for that list.

Article 102.

In the election of members of the House of Representatives on a constituency basis, the person having the right to vote shall cast ballot for one candidate in each constituency.

The determination of the ratio of the number of inhabitants to one member shall be made by reference to the division of such number of inhabitants throughout the country as evidenced in the census announced in the year preceding the year of election by the number of four hundred members of the House of Representatives.

The number of members of the House of Representatives of each Changwat shall be determined by the division of the number of inhabitants in that Changwat by such number of inhabitants per one member as determined under paragraph two. Any Changwat with inhabitants below the number of inhabitants per one member under paragraph two shall have one member of the House of Representative. Any Changwat with more inhabitants than the number of inhabitants per one member shall have an additional member of the House of Representatives for every such number of inhabitants as representing the number of inhabitants per one member.

Upon the number of members of the House of Representatives of each Changwat being obtained under paragraph three, if the number of members of the House of Representatives is still less than four hundred, any Changwat with the largest fraction remaining from the determination under paragraph three shall have an additional member of the House of Representatives and the addition of the members of the House of Representatives in accordance with such procedure shall be made to Changwats in respective order of fractions remaining from the determination under paragraph three until the number of four hundred is obtained.

1998 Organic Law amended 1999 and 2000 on the Election of Members of the House of Representatives and Installation of Senators, Articles 75 and 76

2011 Organic Law on the Election of Members of the House of Representatives and Installation of Senators, Articles 28-30

Constitutional court has ruled that a general election held in February 2014 was invalid, setting the stage for new elections.