(b) If a petition is filed with the Authority—
(1) by any person alleging—
by any person seeking clarification of, or an amendment to, a certification then in effect or a matter relating to representation;
the Authority shall investigate the petition, and if it has reasonable cause to believe that a question of representation exists, it shall provide an opportunity for a hearing (for which a transcript shall be kept) after reasonable notice. If the Authority finds on the record of the hearing that a question of representation exists, the Authority shall supervise or conduct an election on the question by secret ballot and shall certify the results thereof. An election under this subsection shall not be conducted in any appropriate unit or in any subdivision thereof within which, in the preceding 12 calendar months, a valid election under this subsection has been held.
(c) A labor organization which—
has been designated by at least 10 percent of the employees in the unit specified in any petition filed pursuant to subsection (b) of this section;
has submitted a valid copy of a current or recently expired collective bargaining agreement for the unit; or
may intervene with respect to a petition filed pursuant to subsection (b) of this section and shall be placed on the ballot of any election under such subsection (b) with respect to the petition.
(d) The Authority shall determine who is eligible to vote in any election under this section and shall establish rules governing any such election, which shall include rules allowing employees eligible to vote the opportunity to choose—
not to be represented by a labor organization.
In any election in which no choice on the ballot receives a majority of the votes cast, a runoff election shall be conducted between the two choices receiving the highest number of votes. A labor organization which receives the majority of the votes cast in an election shall be certified by the Authority as the exclusive representative.
(f) Exclusive recognition shall not be accorded to a labor organization—
in the case of a petition filed pursuant to subsection (b)(1)(A) of this section, if there is not credible evidence that at least 30 percent of the employees in the unit specified in the petition wish to be represented for the purpose of collective bargaining by the labor organization seeking exclusive recognition;
(3) if there is then in effect a lawful written collective bargaining agreement between the agency involved and an exclusive representative (other than the labor organization seeking exclusive recognition) covering any employees included in the unit specified in the petition, unless—
the petition for exclusive recognition is filed not more than 105 days and not less than 60 days before the expiration date of the collective bargaining agreement; or