Any or all of the street railway companies operating in the District of Columbia are hereby authorized and empowered to merge or consolidate, either by purchase or lease by 1 company of the properties, and/or stocks or securities of any of the others, or by the formation of a new corporation to acquire the properties and/or stocks or securities and to succeed to the powers and obligations of each or any of said companies under such terms and conditions as may be agreed upon by a vote of a majority in amount of the stock of the respective corporations and as may be approved by the Public Service Commission of the District of Columbia; provided, that no merger of said companies shall be finally consummated until the same is approved by a joint resolution of Congress. Such new corporation shall be incorporated under the provisions of Chapters 1, 2, and 4 of Title 29, as far as applicable, with issues of stock at a stated par value and/or of no par value, as may be approved by the Public Service Commission. Congress reserves the right to alter, amend, or repeal this section or any provision thereof.