The Election Commission of Thailand (ECT) provides clarification on the procedures for the 2024 selection of the senator, as well as the ECT’s resolution on the inquiry files concerning the selection, following its consideration on 14 September 2026.

The key details are as follows:

1. The 2024 Selection of the Senator

The Royal Decree calling for the Selection of Senators B.E. 2567 (2024) came into force on 11 May 2024. The ECT subsequently determined the application period and the dates for the selection of the senator, which was conducted at three levels: district, provincial, and national. Applications were accepted from 20–24 May 2024.

The selection of the senators used a “self-selection” system, under which candidates were divided into 20 groups based on their occupations and experience. Candidates were required to proceed through the selection process in sequence, from the district level to the provincial level and then to the national level.

The district-level selection was held on 9 June 2024, with successful candidates advancing to the provincial level.

The provincial-level selection was held on 16 June 2024, with successful candidates advancing to the national level.

The national-level selection was held on 26 June 2024 as the final stage. Provincial-level candidates from across the country participated in the self-selection process to select 200 Senators from 20 groups, with 10 members per group, along with a reserve list of 5 members per group.

The ECT announced the certified results of the selection of the senator, on 10 July 2024.

2. Inquiry Files into the Selection of Senators in Cases of Reasonable Suspicion or Apparent Facts

On 18 March 2025, the ECT considered matters concerning the national-level selection
of the senators following a report from the Department of Special Investigation (DSI), pursuant to its Confidential and Urgent Letter No. Yothor 0824/0050 dated 3 February 2025. The investigation identified information and evidence concerning the alleged establishment of a network of individuals to facilitate activities relating to the selection of the senator in a manner that may have violated the Constitution and the Organic Act on the Acquisition of Senators B.E. 2561 (2018). The investigation indicated, among other matters, that groups of candidates had allegedly been organized and compensation determined at different levels. Meetings had allegedly been arranged among persons eligible to participate in the national-level selection of the senator to prepare voting lists, deposits had allegedly been paid, and arrangements had allegedly been made for travel to the selection venue. The results of the morning round and the cross-group round appeared to correspond with those voting lists.

The ECT further determined that there were sufficient facts, circumstances, and evidence to order an investigation into possible violations of the Organic Act on the Acquisition of Senators B.E. 2561 (2018), including Sections 70, 36, 77 (1), 79, and 81.

Accordingly, at Meeting No. 26/2025 on 18 March 2025, the ECT resolved to conduct
an inquiry to establish the relevant facts and evidence.

3. Timeline of the Investigation the key stages from the national-level selection of the senators through the ECT’s resolution are as follows:

Inquiry in cases of Reasonable Suspicion or Apparent Facts

·       3 February 2025: The DSI submitted information concerning alleged offenses relating
to the selection of the senators.

·       18 March 2025: The ECT resolved to order an inquiry into the matter based on
the DSI report.

·       19 March 2025: The ECT appointed the Central Investigation and Inquiry Committee
No. 26 to conduct the inquiry on the selection of Senators

·       July 2024 – March 2025: A total of 619 objections concerning the selection of the senator were submitted, of which 597 cases had been adjudicated by the ECT. The ECT also considered the qualifications and prohibited characteristics of 1,767 persons who had applied to become Senators.

·       15 September 2025: The Deputy Secretary-General of the ECT, acting for the Secretary-General, prepared an opinion and supporting reasons for submission to the Subcommittee on Adjudication of Problems or Disputes. (Pursuant to Section 37 of the Organic Act on the Election Commission B.E. 2560 (2017) and Clause 78 of the Regulations of the Election Commission on Investigation, Inquiry, and Adjudication B.E. 2561 (2018)).

·       16 September 2025: The ECT appointed Subcommittee No. 36 on Adjudication
of Problems or Disputes to consider the investigation files and all relevant evidence. (Pursuant to Section 37 of the Organic Act on the Election Commission B.E. 2560 (2017) and Clause 74 of the Regulations of the Election Commission on Investigation, Inquiry, and Adjudication B.E. 2561 (2018))

·       26 February 2026: Subcommittee No. 36 prepared its opinion and supporting reasons
for submission to the ECT. (Pursuant to Section 37 of the Organic Act on the Election Commission B.E. 2560 (2017) and Clause 79 of the Regulations of the Election Commission on Investigation, Inquiry, and Adjudication B.E. 2561 (2018))

·       30 March 2026: The Chairman of the ECT ordered the matter to be placed on the ECT meeting agenda. Preparations, document duplication, preliminary consideration, and examination of the investigation files were undertaken. (The files contained a total
of 75,722 pages.)

·       8 June – 28 August 2026: The ECT considered the investigation files over 11 meetings.

·       14 September 2026: The ECT considered and adopted its resolution.

4. Summary of the ECT’s Resolution

On 14 September 2026, the ECT considered the investigation files concerning the 2024 selection of the senator and adopted the following resolution:

4.1 Complainants:                67 persons

4.2   Respondents:                 427 persons

4.3   Inquiry files:                   75,722 pages

4.4 The ECT resolved to file petitions with the Supreme Court and initiate criminal proceedings against a total of 77 persons, with the details as follows:

(1) Members of the Senate (Senators)

     (Holding office at the time the petition was filed)        Number: 26 persons

(2) Spare Members of the Senate (Senators)

     (Included in the list)                                                  Number: -   persons

     (3) Persons eligible to vote in the Selection of the Senators

         (Excluding persons under items (1) and (2))                   Number: 36 persons

     (4) Political party executive committee members /

          Members of the House of Representatives /

          Persons holding political positions                               Number: -   persons

     (5) Other persons                                                           Number: 15 persons

5. A total of 7 charges are involved.

   5.1 Allegation No. 1 Section 76, Paragraph One, of the Organic Act on the Acquisition of Senators B.E. 2561 (2018), Any executive member of a political party or holder of any other position in a political party, member of the House of Representatives, member of a local assembly, local administrator or holder of a political position, who by any means performs an act assisting any candidate in being selected as a senator or preventing any candidate from being selected

A person who violates this provision shall be liable to imprisonment for a term of 1-10 years and to a fine of 20,000 - 200,000 Baht and the Court shall order revocation of such person’s right to candidacy in an election

The ECT resolved to file petitions with the Supreme Court and initiate criminal proceedings under this charge against 0 persons.

1.          Party Executives / MPs / Political Office Holders: - persons

2.          Other Persons: - persons

   5.2 Allegation No. 2 Section 76, paragraph two, of the Organic Act on the Acquisition of Senators B.E. 2561 (2018) provides that: Any candidate who gives consent to an executive member of a political party or a holder of any other position in a political party, a member of the House of Representatives

A person who violates this provision shall be liable to imprisonment for a term 1-10 years and to a fine of 20,000 - 200,000 Baht and the Court shall order revocation of such person’s right to candidacy in an election.

The Election Commission resolved to file petitions with the Supreme Court and initiate criminal proceedings against a total of - persons, with the details as follows:

(1) Members of the Senate (Senators)

    (Holding office at the time the petition was filed)                 Number: - persons

(2) Spare Members of the Senate (Senators)

    (Included in the list)                                                         Number: - persons

 (3) Persons eligible to vote in the Selection of the Senators

    (Excluding persons under items (1) and (2))                         Number: - persons

    5.3 Allegation No. 3 Section 36, paragraph one, in conjunction with Section 70 of the Organic Act on the Acquisition of Senators B.E. 2561 (2018) provides that: “The personal introduction of oneself is not conducted in accordance with the methods and conditions prescribed by the Election Commission.” Such conduct constitutes a violation of Section 36, paragraph one, in conjunction with Section 70 of the Organic Act on the Acquisition of Senators B.E. 2561 (2018).

 A person who violates this provision shall be subject to imprisonment for a term not exceeding 1 year or a fine not exceeding 20,000 baht, or both, and the Court shall order the revocation of the person's right to vote for a period of 5 years.

The Election Commission resolved to file petitions with the Supreme Court and initiate criminal proceedings against a total of 36 persons, with the details as follows:

 (1) Members of the Senate (Senators)

   (Holding office at the time the petition was filed)                  Number: 26 persons

 (2) Spare Members of the Senate (Senators)

   (Included in the list)                                                          Number: - persons

 (3) Persons eligible to vote in the Selection of the Senators

   (Excluding persons under items (1) and (2))                          Number: 1 person

 (4) Political party executive committee members /

 Members of the House of Representatives /

 Persons holding political positions                                      Number: - persons

 (5) Other persons                                                                 Number: 9 persons

   5.4 Allegations Nos. 4–7

    Allegation No. 4 Section 77, paragraph one (1) Organic Act on the Acquisition of Senators B.E. 2561 (2018) “procuring, giving, offering to give, promising to give or preparing to give property or any other benefit capable of calculation into monetary value to any person;”

A person who violates this provision shall be subject to imprisonment for a term not exceeding 1 year or a fine not exceeding 20,000 baht, or both, and the Court shall order the revocation of the person's right to vote for a period of 20 years and shall be deemed to be predicate offences under the law on anti-money laundering and the Commission shall have the power to refer the matter to the Anti-Money Laundering Office for taking action in accordance with its duties and powers.

Allegation No. 5 Section 77, paragraph one (3) Organic Act on the Acquisition of Senators B.E. 2561 (2018) “giving a treat or agreeing to give a treat to any person.”

A person who violates this provision shall be subject to imprisonment for a term not exceeding 1 year or a fine not exceeding 20,000 baht, or both, and the Court shall order the revocation of the person's right to vote for a period of 20 years

Allegation No. 6 Section 79 Organic Act on the Acquisition of Senators B.E. 2561 (2018) “Any person who demands or accepts property or any other benefit for the purpose of applying for the selection or not applying for the selection for the benefit of any candidate.”

A person who violates this provision shall be subject to imprisonment for a term not exceeding 1 year or a fine not exceeding 20,000 baht, or both, and the Court shall order the revocation of the person's right to vote for a period of 20 years

Allegation No. 7 Section 81 Organic Act on the Acquisition of Senators B.E. 2561 (2018) “Any person entitled to make the selection who demands, accepts or agrees to accept money, property or any other benefit for himself or any other person in return for selecting or refraining from selecting any person.”

A person who violates this provision shall be subject to imprisonment for a term of 1 - 5 years, or a fine of 20,000 to 100,000 baht, or both, and the Court shall order the revocation of the person’s right to vote for a period of 10 years.

The Election Commission resolved to file petitions with the Supreme Court and initiate criminal proceedings on allegations Nos. 4–7 involve a total of 77 persons, with the details as follows:

(1) Members of the Senate (Senators)
(Holding office at the time the petitions were filed)       Number: 26 persons

(2) Spare Members of the Senate (Reserve Senators)
(included in the list)                                                  Number: – persons

(3) Persons entitled to select Senators
(excluding persons under items (1)–(2))                        Number: 36 persons

(4) Members of the House of Representatives /
Persons holding political positions                               Number: – persons

(5) Other persons                                                           Number: 15 persons

6. Following the Election Commission’s decision on the inquiry file concerning the selection of Senators, the following procedures shall be undertaken:

6.1 The Election Commission shall prepare its decision on the inquiry file concerning
the selection of Senators within 60 days.

6.2 A petition shall be filed with the Supreme Court within 60 days.

6.3 Once the Supreme Court issues an order accepting the petition for consideration,
if the person concerned is a Senator, the person shall suspend the performance of duties until the Supreme Court renders its judgment.

6.4 If the Supreme Court renders a judgment finding that an offence has been committed, the Senator’s membership shall terminate as from the date on which the Senator suspended the performance of duties.

7. Procedures in the Event of a Vacancy in the Position of Senator

In the event that a judgment or order of the Court results in a vacancy in the position of Senator, the procedures shall be carried out in accordance with Section 45 of the Organic Act on the Acquisition of Senators B.E. 2561 (2018), as follows:

7.1 In the event that the number of Senators in any group is incomplete, whether due to a vacancy or any other reason, other than the expiration of the term of the Senate:

The President of the Senate shall announce in the Government Gazette the advancement of a person on the spare list of that group to fill the vacant position of a Senator, in accordance with the order of the spare list. Such person shall hold office only for the remaining term of the Senate. Pending the person’s assumption of office, the Senate shall consist of only existing Senators.

7.2 In the event that a person on the spare list of a particular group is required to be advanced to fill a vacant position of Senator, but there are no remaining persons on the spare list of that group for any reason:

The President of the Senate shall draw lots to determine from which other group that still has persons remaining on its spare list. A person shall be advanced and hold office as a Senator. The drawing of lots under this paragraph shall apply only to that particular advancement.

7.3 In the event that no group has any person remaining on its reserve list to be advanced to hold office:

The Senate shall consist of only existing Senators. However, if the number of Senators remaining is less than one-half of the total number of Senators, and more than one year remains in the term of the Senate, a selection for Senators shall be conducted to fill the vacant positions within 60 days from the date on which the number of Senators falls below one-half of the total number. In such a case, the persons selected shall hold office only for the remaining term of the Senate.

For more information on the election, please visit the Office of the Election Commission’s website at www.ect.go.th or contact the Election Commission Hotline at 1444.