20(1) of the Act, with which we are concerned, is in these terms: "(1) Every officer or other employee of an existing air company (except a director, managing agent, manager or any other person entitled to manage the whole or a substantial part of the business and affairs of the company under a special agreement) employed by that company prior to the first day of July, 1952, and still in its employment immediately before the appointed day shall, in so far as such officer or other employee is employed in connection with the undertaking which has vested in either of the Corporations by virtue of this Act, become as from the appointed date an officer or other employee, as the case may be, of the Corporation in which the undertaking has vested and shall hold his office or service therein by the same tenure, at the same remuneration and upon the same terms and conditions and with the same rights and privileges as to pension and gratuity and other matters as he would have held the same under the existing air company if its undertaking had not vested in the Corporation and shall continue to do so unless and until his employment in the Corporation is terminated or until his remuneration, terms or conditions are duly altered by the Corporation : Provided nothing contained in this section shall apply to any officer or other employee who has, by notice in writing given to the Corporation concerned prior to such date as may be fixed by the Central Government by notification in the official gazette 816 intimated his intention of not becoming an officer or other employee of the Corporation." After the Act was passed, notice was sent on June 17, 1953, to each employee of all the air companies which were being taken over by the proposed Corporation m and he was asked to inform the officer on special duty by July 10, 1953, if he desired to give the notice contemplated by the proviso to section 20(1).