The 2026 Negeri Sembilan constitutional crisis is an ongoing constitutional and customary administrative crisis that began on 17 April 2026 in Negeri Sembilan, Malaysia. The crisis centres on a jurisdictional clash between the institution of the Yang di-Pertuan Besar of Negeri Sembilan, Tuanku Muhriz of Negeri Sembilan, and the institution of the (The Four Ruling Chiefs) led by the Undang of Sungei Ujong, Mubarak Dohak, involving the state government.
The turmoil is rooted in an internal customary administration dispute in the Luak of Sungei Ujong that began in 2024, which subsequently led to the intervention of the Council of the Yang di-Pertuan Besar and Ruling Chiefs (DKU).
On 17 April 2026, the DKU declared the retroactive dismissal of Mubarak Dohak. In retaliation, on 19 April 2026, Mubarak Dohak, with the majority support of the Undang Yang Empat, declared the removal of Tuanku Muhriz from the throne based on an interpretation of Article 10 of the Laws of the Constitution of Negeri Sembilan 1959. The faction also named Tunku Nadzaruddin ibni Almarhum Tuanku Ja'afar as the new Yang di-Pertuan Besar. The legality of both declarations have been disputed.
The crisis partially contributed to the dissolution of the state assembly and subsequent state election, which saw a coalition between Barisan Nasional and Perikatan Nasional (BN–PN) come to power, replacing the preceding Pakatan Harapan–Barisan Nasional (PH–BN) government. Following the BN–PN state executive council's recognition of the declaration removing Tuanku Muhriz, he dismissed all ten of its members except for Menteri Besar Ismail Lasim. The Ismail-led state executive council also attempted to suspend the state secretary and legal advisor but was unsuccessful.
Background and factions Those aligned with Tuanku Muhriz include 11th Undang of Sungei Ujong (since 2026), 17th Undang of Jelebu Azrin Khairi (since 2026), 22nd Undang of Rembau Hassan Ab Hamid (since 2026), Tunku Besar Seri Menanti Tunku Ali Redhauddin (since 2009), and 8th Menteri Besar of Negeri Sembilan Aminuddin Harun (2018 to 2026).
Supporters of Tunku Nadzaruddin include 10th Undang of Sungei Ujong Mubarak Dohak (since 1993), 16th Undang of Jelebu Maarof bin Mat Rashad (since 2019), 21st Undang of Rembau (since 2024), Dato' Shahbandar of Sungei Ujong Badarudin Abdul Khalid (until 2026), Tunku Besar Tampin (the hereditary ruler of Tampin) Tunku Syed Razman (since 2005), and 9th Menteri Besar Ismail Lasim (since 2026).
The Adat Perpatih System The administrative and constitutional framework of Negeri Sembilan is anchored in Adat Perpatih, a customary law originating from Minangkabau, Sumatra, founded by Dato' Perpatih Nan Sebatang. Unlike absolute monarchies or systems of primogeniture (where the throne passes from father to the eldest son) practiced in other Malay states, Adat Perpatih employs a "bottom-up" hierarchical power structure that mirrors democratic principles.
In the Adat Perpatih hierarchy, power originates from the common people and is stratified through socio-political units:
Perut: The smallest unit, consisting of maternal descendants of the same lineage. It is led by a Buapak, who is elected by consensus of the anak buah (family members). Suku: A group of several Perut forming a larger community. It is led by a Dato' Lembaga, appointed by consensus among the Buapak. Luak: Territorial administrative districts (such as Luak Sungei Ujong, Jelebu, Johol, and Rembau). Each luak is headed by an Undang, elected and appointed by the Dato' Lembaga of their respective luak, with the consent of the Ibu Soko (female elders who hold the customary heritage). Yang di-Pertuan Besar (Yamtuan Besar): The Head of State (ruler) who does not inherit the throne automatically. Instead, the ruler is elected and appointed by the consensus of the four principal territorial chiefs, known as the Undang Yang Empat.
Mechanism for removing the Yang di-Pertuan Besar The Laws of the Constitution of Negeri Sembilan 1959 allow for the removal of the Yang di-Pertuan Besar by the four ruling chiefs. They may call upon the Yang di-Pertuan Besar to withdraw from performing his duties for a period or to abdicate and relinquish his position entirely if he should have "developed any great and serious defect derogatory to the quality of the Yang di-Pertuan Besar [...] become possessed of any base quality on account of which He would not be permitted by the Hukum Syarak [...] done any overt act detrimental to the sanctity, honour, and dignity of a Yang di-Pertuan Besar [...] or has deliberately disregarded the provisions of this Constitution," with any such call taking immediate effect provided a proclamation is issued by the four ruling chiefs and the Menteri Besar.
The Council of the Yang di-Pertuan Besar and Ruling Chiefs The Dewan Keadilan dan Undang (DKU) or Council of the Yang di-Pertuan Besar and Ruling Chiefs is an advisory body relating to Malay customs in the state, possessing jurisdiction over matters "relating to the election or selection to or removal from or vacation of office" of the Undangs of Sungei Ujong, Jelebu, Johol, Rembau, and the Tunku Besar Tampin. The body consists of the Yang di-Pertuan Besar, the four Undangs, the Dato' Shahbandar of Sungei Ujong, the Tunku Besar Tampin, and the Tunku Besar Seri Menanti, and its advice is final and cannot be challenged.
The conflict
Initial conflict within luak Sungei Ujong The seeds of this constitutional crisis originated from internal turmoil within the luak of Sungei Ujong around 2024.
The 10th Undang of Sungei Ujong, Mubarak Dohak, claimed that two customary chiefs, one of them being the Dato Andulika Mandalika Zainol Ariffin, had established an entity named 'Majlis Dato-Dato Lembaga Adat Sungei Ujong' (Council of Customary Chiefs of Sungei Ujong) without his approval and that the Council had applied for funds amounting to RM170,000 from the Negeri Sembilan Museum Board and the Member of Parliament (MP) for Seremban, Anthony Loke between 2019 and 2024.
When the office of the Undang was met with a request for a financial report concerning the funds granted to the Council, the office claimed to be unaware of the Council's existence and that it possessed no bank account where the funds were supposedly transferred until 1 July 2024. Following this, an investigation by the office of the Undang was said to have found evidence of abuse of power, resulting in the dismissal of the two chiefs on 1 December 2024. However, the two chiefs contested their dismissal, arguing that relevant procedures were not followed. Zainol Ariffin further claimed that a police investigation in 2024 had found no evidence wrongdoing, and that Mubarak himself had donated funds to the Council.
On 13 May 2025, the Telaga Undang, who acts an arbitrator in customary matters within the luak of Sungei Ujong, and the Waris Klana Hulu (Descendants of Klana Hulu), of which Mubarak Dohak is a member, removed him as Dato' Klana Petra and thus Undang of Sungei Ujong.
State-wide conflict and installation of Tunku Nadzaruddin as pretender The matter was escalated to the Council of the Yang di-Pertuan Besar and Ruling Chiefs (DKU), which recommended that Mubarak's removal be accepted following a review of 33 claims of customary violations against him on 17 April 2026. On 19 April, the Undang Yang Empat, led by Mubarak, announced the removal of Tuanku Muhriz as the Yang di-Pertuan Besar, citing deliberate breaches in the discharge of royal duties, and the election of Tunku Nadzaruddin Tuanku Ja'afar as his replacement. The next day, Mubarak's removal as the Undang of Sungei Ujong was upheld by the DKU, and the state government under Aminuddin Harun regarded the Undang Yang Empat's declaration as illegitimate, citing Mubarak's prior dismissal. Aminuddin Harun also refused to sign the proclamation of Tuanku Muhriz's removal issued by the Undang Yang Empat, when it was presented to him on 20 April.
However, the DKU's decision was criticised by constitutional expert Rais Yatim, a former Menteri Besar of the state and a researcher of Adat Perpatih, who claimed the DKU had ignored objections from Tunku Syed Razman, the Tunku Besar Tampin, and Muhammad Abdullah, the Undang of Johol. He also described the action as overstepping the boundaries of the customary separation of powers, claiming that the DKU is legally only an advisory body. He further emphasized that the power to dismiss an Undang rests solely upon the consensus of the Lembaga (customary chiefs) within the luak of Sungei Ujong itself.
Following Aminuddin's dismissal of the proclamation removing Tuanku Muhriz, the constitutional crisis veered into the political realm as the four ruling chiefs and Tunku Besar Tampin, the hereditary ruler of Tampin, called for him to resign. The four ruling chiefs boycotted the opening of the state assembly on 23 April, resulting in its postponement. On 27 April, 14 members of Barisan Nasional in the state legislative assembly withdrew their support for Aminuddin, accusing him of disrespecting traditional institutions and mishandling the crisis, though this decision was ultimately reversed by Barisan Nasional's national leadership. Nevertheless, the state assembly was dissolved on 5 June to pave the way for an early election after a protracted deadlock.
On the same day, a special sitting of the Council of the Yang di-Pertuan Besar and Ruling Chiefs called by the four ruling chiefs, the Tunku Besar Tampin, and Dato' Shahbandar of Sungei Ujong was held at the residence of Tunku Besar Tampin. Police initially prevented customary leaders and dignitaries from entering the premises. The special sitting was held with the intention of proclaiming Tunku Nadzaruddin as the 12th Yang di-Pertuan Negeri, but he was similarly prevented by police from attending and was instead proclaimed at a hotel in Malacca. An injunction was subsequently issued by the Seremban High Court preventing the four ruling chiefs and the Tunku Besar Tampin from convening the DKU or taking any decisions until the question of jurisdiction and justiciability related to the dispute was determined. The injunction also prevented the removal of Raja Norazli Raja Nordin as the body's secretary over his refusal to schedule a meeting to discuss the crisis.
Installation of new Undangs; UMNO-led state government supports pretender On 27 June, Tuanku Muhriz formalised the installation of two new Undangs, Faris Johari as the 11th Undang of Sungei Ujong, and Hassan Ab Hamid as the 22nd Undang of Rembau; the position of Undang of Rembau was declared vacant despite the installation of in 2024, as Abd Rahim's appointment was supposedly never formally proclaimed. On 30 July, the Dato' Shahbandar of Sungei Ujong, Badarudin Abdul Khalid, was removed from his role, and on 31 July, the Undang of Jelebu, Maarof Mat Rashad, was removed by the DKU, citing customary violations made effective 31 May 2025.
The 2026 Negeri Sembilan state election held on 1 August returned a Barisan Nasional majority. While Jalaluddin Alias was considered for the position of Menteri Besar, having played a leading role in the coalition's withdrawal of support for Aminuddin in April, Ismail Lasim was ultimately chosen; the appointment of the Menteri Besar being the sole responsibility of the Yang di-Pertuan Besar. Jalaluddin, along with a number of UMNO assemblypersons, were absent from Ismail's swearing-in ceremony on 2 August.