Issuance of permits for any part of proposed discretionary projects shall be withheld until environmental documents have been approved as required by these guidelines. All departments, officers and public employees of the County vested with the duty or authority to issue permits, certificates or licenses shall issue no permit, certificate or license for uses, buildings or purposes in conflict with the provisions of these guidelines, and any such permit, certificate or license issued in conflict with the provisions of these guidelines shall be null and void.