President of the Senate and Speaker of the House of Representatives
Section 50(2) · 1999 Constitution (2004 edition)
What Constitution says
(2) The President or Deputy President of the Senate or the Speaker or Deputy Speaker of the House of Representatives shall vacate his office - (a) if he ceases to be a member of the Senate or of the House of Representatives, as the case may be, otherwise than by reason of a dissolution of the Senate or the House of Representatives; or (b) when the House of which he was a member first sits after any dissolution of that House; or (c) if he is removed from office by a resolution of the Senate or of the House of Representatives, as the case may be, by the votes of not less than two-thirds majority of the members of that House.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 43. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections