( 1 ) THIS appeal is directed against the order of the central Administrative tribunal, Calcutta bench dated 23/9/1993, passed in OA No. 8 of 1992 and OA No. 9 of 1992. Special leave was rejected as against OA No. 8 of 1992, but had been granted as against order in OA No. 9 of 1992. The question for consideration in this appeal is whether the service rendered by Respondents 3 to 9 on ad hoc basis prior to their regularisation by letter dated 25/10/1984 can at all be taken into account for determining their seniority in the rank of Assistant Engineer. It is not disputed that in exercise of the power conferred under Article 309 of the Constitution, the President has framed a set of Rulescalled "andaman and Nicobar (PWD) Group A and Group B Posts Recruitment Rules, 1980" (hereinafter referred to as "the Rules" ). Respondents 3 to 7 had been promoted on ad hoc basis to continue as Assistant Engineer. A Departmental Promotion Committee considered the case of regular promotion on 30/8/1982, but the said Committee found that unless and until the reserved posts are dereserved, no regular promotion can be given to the said respondents. The Departmental Promotion Committee, however, recommen