JUDGMENT

RAY, C. J. (Majority Judgment) :—This appeal is by certificate from the judgment dated 19 April, 1974 of the High Court of Kerala.

2. This appeal concerns the validity of Rule 13AA of the Kerala State and Subordinate Services Rules, 1958 hereinafter called the Rules and two orders which are marked P-2 and P-6.

3. In order to appreciate Rule 13AA, it is necessary to refer to Rules 12, 13A, 13AA. These rules were framed in exercise of the powers conferred by the proviso to Article 309 of the Constitution. These rules came into existence on 17 December, 1958.

4. "Promotion" is defined in Rule 2 (11) to mean the appointment of a member of any category or grade of a service or a class of service to a higher category or grade of such service or class.

5. Rule 12 states that where general educational qualifications, special qualifications or special tests are prescribed by the Special Rules of a service for any category, grade or post therein, or in a class thereof, which are not prescribed for a category or grade in such service or class carrying a lower rate of pay and no member in the category or grade carrying the lower rate of pay is eligible for promotion to such category, grade or post a member in such lower category or grade may be promoted to the category or grade carrying the higher rate of pay temporarily until a member of the former category or grade qualified under this rule is available for promotion. A member temporarily promoted under this rule shall not by reason only of such promotion, be regarded as a probationer in the category or grade to which he has been promoted, or be entitled to any preferential claim to future promotion.

6. Rule 13 speaks of special qualifications. Rule 13 does not concern this appeal.

7. The two rules which are of importance in this appeal are Rules 13A and 13AA. They are as follows:-

"13A. Special and Departmental Tests - Temporary exemption for promotion.- Notwithstanding anything contained in Rule 13, where a pass in a special or departmental test is newly prescribed by the Special Rules of a service for any category, grade or post therein or in any class thereof, a member of a service who has not passed the said test but is otherwise qualified and suitable for appointment to such class, category, grade or post may within 2 years of the introduction of the test be appointed thereto temporarily. If a member so appointed does not pass the test within two years from the date of introduction of the said test or when the said test also involves practical training within two years after the first chance to undergo such training he shall be reverted to the class, category or grade or post from which he was appointed and shall not again be eligible for appointment under this rule:

Provided that a person so reverted shall not by reason only of the appointment under this rule be entitled to any preferential claim to future appointment to the class, category, grade or post, as the case may be to which he had been appointed under this rule:

Provided further that the period of temporary exemption shall be extended by two years in the case of a 494 person belonging to any of the scheduled castes or scheduled tribes.

Provided also that this rule shall not be applicable to tests prescribed or purposes of promotion of the executive staff below the rank of Sub-Inspectors belonging to the Police Department."

"13AA. Notwithstanding anything contained in these rules, the Government may, by order, exempt for a specified period, any member or members, belonging to a Scheduled Caste or a Scheduled Tribe, and already in service, from passing the tests referred to in Rule 13 or Rule 13A of the said Rules.

Provided that this rule shall not be applicable to tests prescribed for purposes of promotion of the executive staff below the rank of Sub-Inspectors belonging to the Police Department."

8. It is necessary to state here that the third proviso to Rule 13A and the proviso to Rule 13AA were introduced with effect from