Source: http://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title29-section159&num=0&edition=prelim
Timestamp: 2019-04-23 00:28:35+00:00

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Representatives designated or selected for the purposes of collective bargaining by the majority of the employees in a unit appropriate for such purposes, shall be the exclusive representatives of all the employees in such unit for the purposes of collective bargaining in respect to rates of pay, wages, hours of employment, or other conditions of employment: Provided, That any individual employee or a group of employees shall have the right at any time to present grievances to their employer and to have such grievances adjusted, without the intervention of the bargaining representative, as long as the adjustment is not inconsistent with the terms of a collective-bargaining contract or agreement then in effect: Provided further, That the bargaining representative has been given opportunity to be present at such adjustment.
The Board shall decide in each case whether, in order to assure to employees the fullest freedom in exercising the rights guaranteed by this subchapter, the unit appropriate for the purposes of collective bargaining shall be the employer unit, craft unit, plant unit, or subdivision thereof: Provided, That the Board shall not (1) decide that any unit is appropriate for such purposes if such unit includes both professional employees and employees who are not professional employees unless a majority of such professional employees vote for inclusion in such unit; or (2) decide that any craft unit is inappropriate for such purposes on the ground that a different unit has been established by a prior Board determination, unless a majority of the employees in the proposed craft unit vote against separate representation or (3) decide that any unit is appropriate for such purposes if it includes, together with other employees, any individual employed as a guard to enforce against employees and other persons rules to protect property of the employer or to protect the safety of persons on the employer's premises; but no labor organization shall be certified as the representative of employees in a bargaining unit of guards if such organization admits to membership, or is affiliated directly or indirectly with an organization which admits to membership, employees other than guards.
the Board shall investigate such petition and if it has reasonable cause to believe that a question of representation affecting commerce exists shall provide for an appropriate hearing upon due notice. Such hearing may be conducted by an officer or employee of the regional office, who shall not make any recommendations with respect thereto. If the Board finds upon the record of such hearing that such a question of representation exists, it shall direct an election by secret ballot and shall certify the results thereof.
(2) In determining whether or not a question of representation affecting commerce exists, the same regulations and rules of decision shall apply irrespective of the identity of the persons filing the petition or the kind of relief sought and in no case shall the Board deny a labor organization a place on the ballot by reason of an order with respect to such labor organization or its predecessor not issued in conformity with section 160(c) of this title.
(3) No election shall be directed in any bargaining unit or any subdivision within which in the preceding twelve-month period, a valid election shall have been held. Employees engaged in an economic strike who are not entitled to reinstatement shall be eligible to vote under such regulations as the Board shall find are consistent with the purposes and provisions of this subchapter in any election conducted within twelve months after the commencement of the strike. In any election where none of the choices on the ballot receives a majority, a run-off shall be conducted, the ballot providing for a selection between the two choices receiving the largest and second largest number of valid votes cast in the election.
Whenever an order of the Board made pursuant to section 160(c) of this title is based in whole or in part upon facts certified following an investigation pursuant to subsection (c) of this section and there is a petition for the enforcement or review of such order, such certification and the record of such investigation shall be included in the transcript of the entire record required to be filed under subsection (e) or (f) of section 160 of this title, and thereupon the decree of the court enforcing, modifying, or setting aside in whole or in part the order of the Board shall be made and entered upon the pleadings, testimony, and proceedings set forth in such transcript.
(1) Upon the filing with the Board, by 30 per centum or more of the employees in a bargaining unit covered by an agreement between their employer and a labor organization made pursuant to section 158(a)(3) of this title, of a petition alleging they desire that such authority be rescinded, the Board shall take a secret ballot of the employees in such unit and certify the results thereof to such labor organization and to the employer.
1959-Subsec. (c)(3). Pub. L. 86–257, §702, substituted "Employees engaged in an economic strike who are not entitled to reinstatement shall be eligible to vote under such regulations as the Board shall find are consistent with the purposes and provisions of this subchapter in any election conducted within twelve months after the commencement of the strike" for "Employees on strike who are not entitled to reinstatement shall not be eligible to vote."
Subsecs. (f), (g). Pub. L. 86–257, §201(d), repealed subsecs. (f) and (g) which required unions to file their constitutions, bylaws and a report, prescribed the contents of the report and directed the filing of annual financial reports, and are now covered by section 431 of this title.
Subsec. (h). Pub. L. 86–257, §201(d), repealed subsec. (h) which related to affidavits showing union's officers free from Communist Party affiliation or belief.
1951-Subsec. (e). Act Oct. 22, 1951, §1(c), struck out par. (1) and renumbered pars. (2) and (3) as (1) and (2).
Subsecs. (f) to (h). Act Oct. 22, 1951, §1(d), struck out "No petition under section 159(e)(1) shall be entertained" wherever appearing.
1947-Act June 23, 1947, amended section generally to allow employees to carry their grievances directly to the employer, to circumscribe certain powers of the Board, to make the union file with the Secretary of Labor its constitution, bylaws, and report before being certified as a bargaining agent, to require annual reports by labor unions, and to require labor unions to file affidavits with the Board showing that none of its officers are affiliated with or believe in the Communist Party.
Amendment by section 702 of Pub. L. 86–257 effective sixty days after Sept. 14, 1959, see section 707 of Pub. L. 86–257, set out as a note under section 153 of this title.
For effective date of amendment by act June 23, 1947, see section 104 of act June 23, 1947, set out as a note under section 151 of this title.
Act June 23, 1947, ch. 120, title I, §103, 61 Stat. 152 , provided that: "No provisions of this title [amending this subchapter] shall affect any certification of representatives or any determination as to the appropriate collective-bargaining unit, which was made under section 9 of the National Labor Relations Act [this section] prior to the effective date of this title [sixty days after June 23, 1947] until one year after the date of such certification or if, in respect of any such certification, a collective-bargaining contract was entered into prior to the effective date of this title [sixty days after June 23, 1947], until the end of the contract period or until one year after such date, whichever first occurs."

References: §702
 §201
 §201
 §1
 §1
 §103