The Civil Servants Act of Pakistan 1973

(1) A person appointed on probation shall, on satisfactory completion of his probation, be eligible for confirmation in service or, as the case may be, a post as may be prescribed.
(2) A civil servant promoted to a post on regular basis shall be eligible for confirmation after rendering satisfactory service for the period prescribed for confirmation therein.
(3) There shall be no confirmation against any temporary post.