Section 20C. For the purposes of this and the preceding section, section twenty-four of chapter one hundred and forty-nine, sections one and six of chapter two hundred and fourteen, and sections thirteen A and thirteen B of chapter two hundred and twenty,—

(a) A case shall be held to involve or to grow out of a labor dispute when the case involves persons who are engaged in the same industry, trade, craft or occupation; or who are employees of the same employer; or who are members of the same or an affiliated organization of employers or employees; whether such dispute is (1) between one or more employers or associations of employers and one or more employees or associations of employees; (2) between one or more employers or associations of employers and one or more employers or associations of employers; or (3) between one or more employees or associations of employees and one or more employees or associations of employees; or when the case involves any conflicting or competing interests in a ''labor dispute'' (as hereinafter defined) of ''persons participating or interested'' therein (as hereinafter defined).

(b) A person or association shall be held to be a person participating or interested in a labor dispute if relief is sought against him or it, and if he or it is engaged in the same industry, trade, craft or occupation in which such dispute occurs, or has a direct or indirect interest therein, or is a member, officer or agent of any association composed in whole or in part of employers or employees engaged in such industry, trade, craft or occupation.

(c) The term ''labor dispute'', when used in the sections hereinbefore referred to, includes any controversy arising out of any demand of any character whatsoever concerning terms or conditions of employment, or concerning the association or representation of persons in negotiating, fixing, maintaining, changing, or seeking to arrange, terms or conditions of employment, regardless of whether the disputants stand in proximate relation of employer and employee.

(d) Except as provided in subsection (e) of this section, the term ''lawful labor dispute'' includes any controversy concerning—

(1) The association or representation of persons in negotiating, fixing, maintaining, changing, or seeking to arrange, terms or conditions of employment;

(2) The recognition or bargaining status of a labor organization;

(3) Rates of pay, wages, hire or tenure or hours of employment, or working conditions;

(4) The execution or performance of an agreement to arbitrate an existing or future labor dispute;

(5) The execution or performance of a collective bargaining agreement containing any lawful provision of a kind commonly found in collective bargaining agreements (including but not limited to any provision requiring as a condition of employment membership in a labor organization which is the exclusive representative of the employees in the appropriate collective bargaining unit covered by such agreement when made); or

(6) Any term or condition of employment which has heretofore been regarded as a lawful objective of concerted activities on the part of employees or labor organization.

The foregoing definition shall be applicable regardless of whether the disputants stand in the proximate relation of employer and employee, but shall not be deemed to include any ''unlawful labor dispute'' or ''unlawful secondary boycott'' as defined in the following subsections:—

(e) The term ''unlawful labor dispute'' includes any controversy arising out of a demand—

(1) That an employer commit a criminal offence or unfair employment practice in violation of chapter one hundred and fifty-one B or unfair labor practice either in violation of chapter one hundred and fifty A, or in violation of the National Labor Relations Act;

(2) That an employer include in a collective bargaining agreement any provision the execution or performance of which would be unlawful;

(3) That an employer recognize or bargain collectively with any labor organization as the representative of its employees in any bargaining unit while another labor organization is the representative of such employees certified by the labor relations commission established by section nine O of chapter twenty-three, or by the National Labor Relations Board, prior to the time said commission, or board, would conduct a new investigation and certification of representatives.

(4) That an employer recognize or bargain collectively with any labor organization as the representative of its employees in any bargaining unit within one year after the labor relations commission established by section nine O of chapter twenty-three has determined in a proceeding under section five of chapter one hundred and fifty A that such employees do not desire to be represented by such labor organization; or

(5) Made by any party to a jurisdictional dispute as defined in section six A of chapter two hundred and fourteen who has failed to abide by any voluntary arbitration procedure applicable to such dispute or to comply with the terms of the arbitration award.

(f) The term ''unlawful secondary boycott'' means any strike, slowdown, boycott, or concerted cessation of work or withholding of patronage or services, arising out of a labor dispute, where an object thereof is to force or require any person not otherwise engaged in such labor dispute to cease using, selling, handling, transporting, or dealing in the products of any other producer, processor, or manufacturer, or to cease doing business with any other person; provided, however, that a secondary boycott may lawfully be directed at a person the greater part of whose current business over a representative period is processing, selling, handling, transporting or otherwise dealing in the goods of an employer primarily interested in a lawful labor dispute or who, by any agreement, understanding or arrangement with such employer, is requiring his own employees to perform work or services which would be done by the employees of such employer in the absence of a labor dispute.