1. In this writ petition, though merely the impugned seniority lists are under challenge, the issue raised in this writ petition has a history of at least quarter century and hence, the factual matrix as has been averred in the affidavit filed in support of the writ petition on behalf of the writ petitioners are culled out and given in nutshell as follows:

(i) The writ petitioners were eligible to be appointed as Assistant Engineers in the Highways Department in the year 1989-90. Based on the request made by the State Government, the Tamil Nadu Public Service Commission (hereinafter referred to as, 'Service Commission') has conducted a competitive examination. These writ petitioners, since had qualified to become Assistant Engineers, had applied and participated in the said competitive examination, and through which, they had been selected and appointed.

(ii) In this regard, the further facts leading to the said recruitment is that a notification was issued on 12.09.1989 by the Service Commission to fill up 60 vacancies for selecting candidates for appointment to the post of Assistant Engineers in the Highways Department for the year 1989-90.

(iii) These writ petitioners after having passed through three stages of the competitive examination became successful and accordingly, these petitioners were selected to the post of Assistant Engineers, by the Service Commission, and based on such selection, these petitioners had been appointed. Pursuant to the said appointment, they joined services from 12.8.1991 onwards.

(iv) Thereafter, these petitioners on the basis of seniority had been promoted as Assistant Divisional Engineers during January 2004. The second respondent has published a provisional seniority list of Assistant Divisional Engineers as on 01.04.2004 vide his proceedings dated 29.4.2004.

(v) Here it is pertinent to state that the private respondents 4 to 18 of this writ petition, had been selected to the post of Assistant Engineers to be appointed in Public Works Department, of course, after going through the competitive examination and selection process conducted by the Service Commission for appointment as Assistant Engineers in the Public Works Department in the year 1985-86. Though these private respondents 4 to 18 had been selected by Service Commission to be appointed as Assistant Engineers in the Public Works Department, for want of vacancies, the Government could not give postings immediately to those respondents, and therefore, after a decision said to have been taken by the Government, after getting necessary concurrence from the Service Commission, all these private respondents from 4 to 18 had been appointed as Assistant Engineers in the Highways Department by order dated 6.9.1989 and infact, the said private respondents had joined in service as Assistant Engineers from 15.9.1989 to 10.8.1990.

(vi) It is also to be noted that since these private respondents though had been selected to the post of Assistant Engineers in the Public Works Department through the competitive examination conducted by the Service Commission, as stated supra, they have been appointed by the second respondent after due decision taken by the Government with a concurrence of the Service Commission as Assistant Engineers at Highways Department by order dated 06.09.1989. Accordingly, they all joined in service.

(vii) It is further to be noted, therefore, these private respondents 4 to 18 claimed to be seniors merely because they entered into service between 9/89 to 8/90 whereas the writ petitioners had entered into service only on 22.01.1992, 14.08.1991, 28.8.1991, 13.11.1991 and 30.6.1993 respectively. Thus, before these writ petitioners came into services, the said private respondents 4 to 18 had entered into services. On that basis seniority had been fixed between these two set of incumbents and accordingly, the second respondent published the seniority list of Assistant Divisional Engineers as on 01.04.2004 dated 29.4.2004 where thes