3. ¹[(1)] This Ordinance shall apply to all employments under the Government, and to such other employment or class of employment ²[* * *], as the Government, being of the opinion that such employment or class of employment is essential for the maintenance of public order or for maintaining services necessary to the life of the community, may, by notification in the official Gazette, declare to be an employment or class of employment to which this Ordinance applies. ³[(2) A declaration under sub-section (1) shall remain in force for a period of six months, but the Government may, by notification in official Gazette, successively extend it for further periods not exceeding six months at a time.]