In the event of a lack of participation in the first round of professional elections, where the provisions of the first paragraph of article L. 2143-23 are applied, the validity of the company or establishment agreement negotiated and concluded with the trade union section representative is subject to its approval by the employees by a majority of the votes cast under conditions determined by decree and in compliance with the general principles of electoral law. In the absence of approval, the agreement is deemed to be unwritten.