( 1 ) THE petitioner and the 3rd respondent were members of the Mysore civil Service. By an order notified on 24th February 1970, the 3rd respondent was appointed by the President of India to the Indian Administrative service in the cadre of Mysore in a substantive capacity against a vacancy in the senior post, shown in item 3 of the Cadre Schedule, with effect from 29th November 1969. The petitioner, who is admittedly a senior in the Mysore Civil Service, impugns the validity of this order and prays for the issue of appropriate writs quashing the said order appointing the 3rd respondent, to the Indian Administrative Service and directing the respondents, viz. , the Union of India and the State of Mysore, to consider the case of the petitioner and to appoint him in a substantive capacity to the Indian Administrative Service cadre post with effect from the date on which it was, according to the petitioner, due to him.

( 2 ) IT is common ground that the appointment of members of the State civil Services to the Indian Administrative Service is governed by a set of rules called the Indian Administrative Service (Appointment by Promotion) regulations, 1955, made purs