SECTION 1. Section nineteen hundred and seventeen of the Administrative Code is amended so as to read as follows :
"SEC. 1917. Letting of contracts for National public works.—When any National public works of construction or repair involves an estimated cost of three thousand pesos or more, the contract therefor, shall, except as herein below provided be awarded by the Director of Public Works to the lowest responsible bidder after publication in the Official Gazette, in accordance with Act Numbered Twenty-nine hundred and thirty, for at least three times extending over a period of at least ten days: Provided, however, That in case of urgent necessity, the Director of Public Works may, with the approval of the President of the Philippines upon the recommendation of the Secretary of Public Works and Communications, execute by administration and without advertising for bids any public work costing three thousand pesos or more.
"In the case of National public works involving an expenditure of less than three thousand pesos, it shall be discretionary with the Director of Public Works either to proceed with the work himself or to let the contract to the lowest bidder after such publication and notice as shall be deemed appropriate or as may be, by regulation, prescribed."