Judgment

R. PATHAK, J.: - By this petition under Article 32 of the Constitution the petitioners challenge the validity of a combined seniority list dated October 30, 1979 of Divisional Medical Officers and of promotions and officiating appointments made on the basis of that seniority list to posts of Medical Superintendents in the Indian Railway Medical. Service.

2. Medical Service in the Indian Railways is structured in ascending levels. At the base, for the purpose of this case, is the cadre of Assistant Divisional Medical Officers Class I (who before January 1, 1973 were described as Assistant Medical Officers Class II). Above them is the cadre of Divisional Medical Officers. The next above is. the cadre of Medical Superintendents. Still higher rank Chief Medical Officers, and the apex of the hierarchy is held by the Director General of Medical Services.

3. There are eight petitioners. They were Assistant Medical Officers Class 11 and had been confirmed in that grade, one petitioner in 1962 and the others in 1963.

4. During the years 1970 to 1972, the petitioners were selected by Departmental Promotion Committees for officiating appointments to the Class I Posts of Divisional Medical Officers, when the Indian Railway Medical Service (District Medical Officers) Recruitment Rules, 1965 were in force. Those rules were repealed and replaced by the Indian Railway Medical Service (District Medical Officers) Recruitment Rules, 1973. Under the Rules of 1965 and the Rules of 1973, the posts of District Medical Officers were treated as selection posts.

5. To give effect to the recommendations of the Third Pay Commission, the scales of pay of existing categories of officers were revised. The existing pay scale of Rs. 350-900 attached to the posts of Assistant Medical Officer was revised and split into two pay scales, a higher Class I scale of Rs. 700-1600 and a lower Class II scale of Rs. 650-1200. The post of Assistant Medical Officers were divided into those carrying the higher pay scale and those carrying the, lower pay scale. A very large number of posts of Assistant Medical Officers were upgraded to the higher pay scale of Rs. 700-1600, and were designated as "Assistant Divisional Medical Officer". The petitioners were placed in the higher pay scale of Rs. 700-1600 and were designated as Assistant Divisional Medical Officers with effect from january 1, 1973. The screening of over 2000 Assistant Medical Officers for the purpose of upgrading them to the higher scale kept the Screening Committee busy from 1974 to 1976 or so, and practically no recruitment was made during those years either by permanent promotion or direct recruitment to the posts of Divisional Medical Officer.

6. The Rules of 1973 were replaced by the Indian Railway Medical Service (Divisional Medical Officers/Senior Medical Officers) Recruitment Rules, 1975. These, in their turn yielded place to the Indian Railway Medical Service (Chief Medical Officers, Additional Chief Medical Officers, Medical Superintendents and Divisional/Senior Medical Officers) Recruitment Rules, 1978. Under the Rules of 1978, promotion is effected on the principle of "non-selection", an expression in the Rules which is construed by the Railway Administration as "seniority-cum-suitability".

7. By a letter No. E(0)I-78/SR-6/14 dated October 10, 1979 the Railway Board published a combined seniority list of Divisional Medical Officers recruited directly or by promotion. The respondents Nos. 4 to 64 were shown in that list. They include promotees as well as direct recruits. The petitioners did not find place in the seniority list. Subsequently, on the basis of their position in that. seniority list, some of the respondents Divisional Medical Officers were appointed to officiate as Medical Superintendents by a Railway Board letter No. E(0)III-81 PN/6/199 dated, August 31, 1981.

8. The petitioners challenge the combined seniority list of Divisional Medical Officers and the officiating promotions to the p