He hails from the remote hamlet Ould Nouar in the Ḥaydan district, Saada Governorate, an area where many northern Yemeni separatists come from. Since youth, he has been acquainted with one of the leaders of the Houthi rebellion, Abdul-Malik al-Houthi, also a key figure in the Zaidi movement since 2004. They are allegedly related by marriage. From 2014 on, al-Mashat was the director of al-Houthis office, his spokesman and representative in peace talks with the United Nations, among other posts.[3][4][5]
In November 2013, he participated in an attack on the town of Dammaj in Saada. From May 2016, he was a member of the Supreme Political Council and was considered a representative of the hawkish faction. He participated in talks with the Chinese authorities in September 2016.[6]
On 19 April 2018, he became Chairman of the Supreme Political Council, after the assassination of Saleh Ali al-Sammad.[5] He is considered chief of the separatist political authorities of northern Yemen, while al-Houthi is head of the movement.[7]
In July 2021, the Supreme Political Council prolonged his tenure for three more terms.[8] Concerning an UN brokered nationwide two month truce of mid-2022, the first since 2016, he declared not to object an extension, while criticizing its terms for "not being encouraging enough".[9]