JUDGMENT

VENKATACHALIAH, J.:— These four Civil Appeals by Special Leave and the Special Leave Petition arise out of and are directed against the common judgment dated 2-9-1987, of the High Court of Delhi in C.W.P. No. 2132 and C.W.P. No. 2082 of 1984 (reported in 1988 Lab IC 434) in which the principal controversy was whether the Rules prescribing different conditions of eligibility for Diploma Holders and Graduates for promotion from the cadre of Junior-Engineers to that of Assistant-Engineers and from the cadre of Assistant-Engineers to that of Executive-Engineers in the Public Works Department of the Delhi Development Authority (DDA) is violative of Arts. 14 and 16 of the Constitution, and would, therefore, require to be declared void.

The High Court, in the writ petitions filed by the Diploma-Holders, has held that such differential treatment of Diploma-Holders and Graduates by the prescription of different standards of service-experience for purposes of eligibility for promotion to the higher cadres is unconstitutional.

2. The D.D.A. which is the appellant in Civil Appeals No. 898 of 1988 and No. 899 of 1988 assails the correctness of the view taken by the High Court. Civil Appeals 896 of 1988 and 897 of 1988 are by the Graduate-Engineers who were respondents before the High Court ,and who are, similarly, aggrieved by the decision under appeal. SLP 6181 of 1986 is by the "DDA Graduate Engineers Association" which seeks to espouse the cause of the Graduate-Engineers. We grant Special Leave in SLP. All the five appeals are heard and disposed of by this common judgment.

C. A. 899 of 1988, C.A. 896 of 1988 and SLP 6181 arise out of C.W.P. 2132 of 1984. C.A. 898 of 1988, C.A. 897 of 1988 arise out of C.W.P. 2082 of 1984.

3. The D.D.A. by its resolution No. 574 dated 13-11-1963 adopted, pronto, the rules Of the Central Public Works Department (CPWD) in regard to the mode of recruitment- both by direct recruitment and by promotion - to the posts of Asst. Engineers. The rules, so adopted, in substance, stipulate and provide that 50% of the posts be filled by direct recruitment or by deputation and that the other 50% be filled up by promotion from the cadre of Junior- Engineers. The cadre of Junior-Engineers itself comprises of both Graduates in Engineering and Diploma-Holders in Engineering. The two categories of officers in the cadre of Junior-Engineers were provided with promotional opportunities to the post of Asst. Engineers in the equal ratio (50% : 50%) of the promotional-posts. Half of it, i.e., 25% was to be filled up by promotion of Graduate Junior-Engineers with three years service- experience as Junior-Engineers; the other 25% to be filled up from Diploma-Holder Junior-Engineers who were diploma holders who had 8 years service-experience as Junior-Engineers.

By resolution No. 105 dated 16-6-1971 the DDA similarly adopted the relevant rules in the CPWD in the matter of recruitment to the posts of Executive-Engineers. The Executive-Engineers post in the DDA thus became purely promotional and Graduate Asst. Engineers with 8 years service-experience and diploma Asst. Engineers with 10 years service- experience were eligible for promotion. No inter se quota between the two class of officers was prescribed.

The following table delineates the effect and purport of the rules adopted under resolution No. 574 dated 13-11-1963 and No. 105 dated 16-6-1971. The table also indicates the mode of initial recruitment to the cadre of Junior-Engineers :

4. In the year 1984 the Diploma-Holders in the cadre of Junior-Engineers and in the cadre of Asst. Engineers sought to assail, by means of two writ petitions presented to the Delhi High Court, the Constitutional validity of the prescriptions made by the rules in the matter of requirement of differential service-experiences between the Graduates and Diploma-Holders for promotion to the higher cadres viz, of Asst. Engineers and Executive-Engineers respectively. They also assailed the promotions o