JUDGMENT

Altamas Kabir, J.

1. This batch of Civil Appeals arises out of a common judgment passed by the Andhra Pradesh High Court in a batch of Writ Petitions allowing the same and setting aside an order dated 10th March, 1998, passed by the Andhra Pradesh Administrative Tribunal in O.A. No. 3599 of 1995 and other connected matters and consequently setting aside G.O. Ms. No. 325 dated 15th June, 1999. In that view of the matter, these Civil Appeals have been taken up for hearing together along with Writ Petition (Civil) No. 566 of 2003.

2. The question to be decided in all the writ petitions was in regard to the procedure to be adopted in determining the seniority of Civil Assistant Surgeons in the Andhra Pradesh Medical & Health Services.

3. In order to appreciate the aforesaid question, it is necessary to set out the background in which the said question arose.

4. The Appellants and the Respondents are members of the Medical and Health Department in the State of Andhra Pradesh. The Appellants herein were promoted to the post of Associate Professors and Professors by virtue of an order passed by the Tribunal, which was approved by the High Court and thereby attained finality. The present dispute concerns the methodology which has been adopted by the State Government for determining the seniority of those who were functioning as Civil Assistant Surgeons and, thereafter, opted for teaching and were appointed as Assistant Professors, which was the feeder post for further promotion to the post of Associate Professors and Professors in the Medical Services.

5. The Medical and Health Department in the State of Andhra Pradesh is governed by Special Rules framed under the proviso to Article 309 of the Constitution, which, as indicated hereinabove, are known as the A.P. Medical and Health Services Rules, hereinafter referred to as "the Health Services Rules". Without going into details of the said Rules, it will be sufficient for our purpose to consider the impact of the said Rules and Government Orders on the question of seniority of Civil Assistant Surgeons in the State Health Services.

6. As early as in 1976, the Government of Andhra Pradesh felt the need for separation of the teaching cadre in medical education. Accordingly, G.O.M. No. 1170 dated 16th December, 1976, was issued separating the teaching cadre from the non-teaching cadre and issuing executive instructions to implement the same. This was also felt to be necessary on account of the advice of the Medical Council of India, which otherwise threatened to de-recognize the medical certificates which had been granted to the students. Accordingly, the Special Rules were issued as mentioned hereinabove, by G.O.M. No. 43 dated 16th January, 1982.

7. Originally, there were no posts of Assistant Professors and only the post of Civil Assistant Surgeons (CAS) was used for teaching in the medical colleges. Among them, those Civil Assistant Surgeons who had acquired Post-Graduate qualifications were given the task of teaching in the teaching colleges. According to the Appellants herein, there was no watertight compartment between the teaching stream and non-teaching stream and whoever either had or subsequently acquired the Post-Graduate qualification was shifted to the teaching stream from the non-teaching stream. As this method was contrary to its Rules and Regulations, the Medical Council of India threatened to withdraw recognition to the medical colleges and subsequently the Rules were amended vide G.O.M. No. 182 dated 29th March, 1988. By virtue of such amendment, the said Rules were divided into three parts, of which the first part consists of only one Rule which provides that the service was to be divided into three branches, viz., Teaching cadre, Non-teaching cadre and Laboratories. Part II of the Special Rules prescribes separate rules for each of the three branches and Part III contains general and common provisions for all the three branches. One of the more important aspects of th