Mallat was invited to sit on the Constitutional Review Committee led by Humam Hamoudi, and completed with the Committee a revision of the Constitution in October 2009. In Summer 2014, he helped the Iraqi president Fouad Masum and Parliamentary Speaker Salim al-Jabouri construct the constitutional argument that put an end to the Prime Ministership of Nouri al-Maliki.[11] In 2016, he helped found Humanist Lebanon, organizing regular demonstrations in the centre of Beirut to end the presidential void in the name of the Constitution.[12]