Judgment

SAWANT, J.:- Special leave granted.

The appellants challenge the validity of the proviso to Rule 17 of the Civil Services Examination Rules, 1990 (1990 Rules) for competitive examination held by the Union Public Service Commission in 1990 for the purpose of filling up the vacancies in various Central Civil Services. Rule 17 reads as follows:

"17. Due consideration will be given at the time of making appointments on the results of the examination to the preferences expressed by a candidate for various services at the time of his application. The appointment to various services will also be governed by the Rules/ Regulations in force as applicable to the respective Services at the time of appointment:

Provided that a candidate who has been approved for appointment to Indian Police Service/ Central Service, Group A mentioned in column 2 below on the results of an earlier examination will be considered only for appointment in services mentioned against that service in column 3 below on the results of this examination.

Sl.No. Service to which approved for appointment Service for which eligible to compete

1 2 3

1. Indian Police Service I.A.S., I.F.S., and Central Services, Group A

2. Central Services I.A.S., I.F.S., and I.P.S.

Provided further that a candidate who is appointed to a Central Service, Group B on the results of an earlier examination will be considered only for appointment to I.A.S., I.F.S., I.P.S. and Central Services Group A.

2. The Central Services Group A consists of as many as 45 services including Indian Revenue Service which comprises among others, Customs Branch (Indian Customs Service, Group A) and CentralExcise Branch (Central Excise Service, Group A). Similarly, Group B Services consist of a number of services. But with them, we are not concerned in this appeal. The result of the aforesaid rule is that a candidate who has been approved for appointment to Indian Police Service can for bettering his prospects, appear in the next examination and on the basis of his performance can be considered for appointment either in I.A.S. or I.F.S. or to any of the Central Services Group A. Similarly, if he has been approved for appointment to any of the Group A Services, he can for bettering his prospects appear in the next examination and on the basis of his performance in that examination, can be considered for appointment in I.A.S. or I.F.S. or I.P.S. but not for appointment in any other Group A Services. There is a similar restriction on the horizontal movement in Group B Services.

The I.A.S,, I.F.S. and I.P.S. form three distinct Services. There was a time when among the three, I.F.S. was considered the most prized service, I.A.S. being the next favoured service. It appears that during recent years, the scales have changed in favour of I.A.S. which is given priority by most of the candidates. The I.P.S. stands by itself, and though may not be considered as covetous as I.A.S. and I.F.S., is prized for itself and has little in common with other Services. This rule, therefore, virtually provided an upward mobility for those appointed to I.P.S. and Central Services Group A, I.P.S. being considered in many respects next only to I. A. S. and I. F. S. However, in one respect, the rule permitted either downward or horizontal movement inasmuch as those selected for appointment to I.P.S. could also move to Group A Services by qualifying themselves in the next examination. However, the horizontal movement among the Group A Services was not permitted and the candidate who was approved for appointment to any of the Group A Services could not on the basis of the results of the next examination opt for any other service in that Group. If he wanted to do so he could do it only by resigning from the Group A Service for which he was approved on the basis of his earlier examination and then take the next examination for competing for the other services in that Group. This was on account of the second proviso to Rule 4 of the said Rule