(1) This section applies to the offices of Secretary to the Cabinet, permanent secretary, head of a department of government, deputy head of a department of government, any office designated by the Public Service Commission as an office of a chief professional adviser to a department of government and any office designated by the Commission, after consultation with the Prime Minister, as an office the holders of which are required to reside outside Saint Lucia for the proper discharge of their functions or as an office in Saint Lucia whose functions relate to external affairs.