Earlier on, National Assembly Speaker Moses Wetangula ruled nomination of Musalia Mudavadi as the Prime Cabinet Secretary was lawful.
This is after Azimio MPs questioned the position's constitutionality.
Speaking at the start of the vetting by the 15-member committee, Wetangula, who is chairing the team, said that the cabinet slot was within the law.
"The committee has already received a total of 22 memorandums to various CS nominees which shall be disclosed to nominees during their vetting. According to our constitution, the president is allowed to have not less than 14 or more than 22 cabinet slots, and I hereby confirm that the Prime Cabinet Secretary is within the law," said Wetangula.
The vetting will run until Saturday, October 22, except for Thursday, October 20, when the country will observe Mashujaa Day.