MR. Chief Justice Warren
delivered the opinion of the Court.
The issue here is whether, in the absence of proof of an antiunion motivation, an employer may be held to have violated §§ 8 (a)(3) and (1) of the National Labor Relations Act1 when it refused to pay striking employees vacation benefits accrued under a terminated collective bargaining agreement while it announced an intention to pay such benefits to striker replacements, returning strikers, and nonstrikers who had been at work on a certain date during the strike.
*28The respondent company and the union 2 entered into a collective bargaining agreement which was effective by its terms until March 31,1963. The agreement contained a commitment by the company to pay vacation benefits to employees who met certain enumerated qualifications.3 In essence, the company agreed to pay specified vacation *29benefits to employees who, during the preceding year, had worked at least 1,525 hours. It was also provided that, in the case of a “lay-off, termination or quitting,” employees who had served more than 60 days during the year would be entitled to pro rata shares of their vacation benefits. Benefits were to be paid on the Friday nearest July 1 of each year.
The agreement was temporarily extended beyond its termination date, but on April 30, 1963, the union gave the required 15 days’ notice of intention to strike over issues which remained unsettled at the bargaining table. Accordingly, on May 16, 1963, approximately 350 of the company’s 400 employees commenced a strike which lasted until December 26, 1963. The company continued to operate during the strike, using nonstrikers, persons hired as replacements for strikers, and some original strikers who had later abandoned the strike and returned to work.4 On July 12, 1963, a number of the strikers demanded their accrued vacation pay from the company. The company rejected this demand, basing its response on the assertion that all contractual obligations had been terminated by the strike and, therefore, none of the company’s employees had a right to vacation pay. Shortly thereafter, however, the company announced that it would grant vacation pay — in the amounts and subject to the conditions set out in the expired agreement— to all employees who had reported for work on July 1, 1963. The company denied that these payments were founded on the agreement and stated that they merely reflected a new “policy” which had been unilaterally adopted.
*30The refusal to pay vacation benefits to strikers, coupled with the payments to nonstrikers, formed the bases of an unfair labor practice complaint filed with the Board while the strike was still in progress. Violations of §§ 8 (a)(3) and (1) were charged. A hearing was held before a trial examiner who found that the company's action in regard to vacation pay constituted a discrimination in terms and conditions of employment which would discourage union membership, as well as an unlawful interference with protected activity. He held that the company had violated §§ 8 (a)(3) and (1) and recommended that it be ordered to cease and desist from its unfair labor practice and to pay the accrued vacation benefits to strikers. The Board, after reviewing the record, adopted the Trial Examiner’s conclusions and remedy.5
A petition for enforcement of the order was filed in the Court of Appeals for the Fifth Circuit. That court first dealt with the company’s contention that the Board had lacked jurisdiction and that the union should have been relegated either to the bargaining table or to a lawsuit under § 301 of the Act,6 since the basic question was one of contract interpretation and application. It noted that the company’s announced policy relating to vacation pay clearly concerned a “term or condition of employment”; since it was alleged that the company had discriminated between striking and nonstriking employees in regard to that term or condition of employment, the complaint stated “an unfair labor practice charge in simplest terms” and the Board had properly exercised its jurisdiction.7 *31Reviewing the substantive aspects of the Board's decision next, the Court of Appeals held that, although discrimination between striking and nonstriking employees had been proved, the Board’s conclusion that the company had committed an unfair labor practice was not well-founded inasmuch as there had been no affirmative showing of an unlawful motivation to discourage union membership or to interfere with the exercise of protected rights. Despite the fact that the company itself had not introduced evidence of a legitimate business purpose underlying its discriminatory action, the Court of Appeals speculated that it might have been motivated by a desire “(1) to reduce expenses; (2) to encourage longer tenure among present employees; or (3) to discourage early leaves immediately before vacation periods.” Believing that the possibility of the existence of such motives was sufficient to overcome the inference of an improper motive which flowed from the conduct itself, the court denied enforcement of the order. 363 F. 2d 130 (1966). We granted certiorari to determine whether the treatment of the motivation issue by the Court of Appeals was consistent with recent decisions of this Court. 385 U. S.. 1000 (1967).
*32The unfair labor practice charged here is grounded primarily in §8 (a) (3) which requires specifically that the Board find a discrimination and a resulting discouragement of union membership. American Ship Building Co. v. Labor Board, 380 U. S. 300, 311 (1965). There is little question but that the result of the company’s refusal to pay vacation benefits to strikers was discrimination in its simplest form. Compare Republic Aviation Corp. v. Labor Board, 324 U. S. 793 (1945), with Teamsters Union v. Labor Board, 365 U. S. 667 (1961). Some employees who met the conditions specified in the expired collective bargaining agreement were paid accrued vacation benefits in the amounts set forth in that agreement, while other employees8 who also met the conditions but who had engaged in protected concerted activity were denied such benefits. Similarly, there can be no doubt but that the discrimination was capable of discouraging membership in a labor organization within the meaning of the statute. Discouraging membership in a labor organization “includes discouraging participation in concerted activities . . . such as a legitimate strike.” Labor Board v. Erie Resistor Corp., 373 U. S. 221, 233 (1963). The act of paying accrued benefits to one group of employees while announcing the extinction of the same benefits for another group of employees who are distinguishable only by their participation in protected concerted activity surely may have a discouraging effect on either present or future concerted activity.
*33But inquiry under § 8 (a) (3) does not usually stop at this point. The statutory language “discrimination . . . to . . . discourage” means that the finding of a violation normally turns on whether the discriminatory conduct was motivated by an antiunion purpose. American Ship Building Co. v. Labor Board, 380 U. S. 300 (1965). It was upon the motivation element that the Court of Appeals based its decision not to grant enforcement, and it is to that element which we now turn. In three recent opinions we considered employer motivation in the context of asserted § 8 (a) (3) violations. American Ship Building Co. v. Labor Board, supra; Labor Board v. Brown, 380 U. S. 278 (1965); and Labor Board v. Erie Resistor Corp., supra. We noted in Erie Resistor, supra, at 227, that proof of an antiunion motivation may make unlawful certain employer conduct which would in other circumstances be lawful. Some conduct, however, is so “inherently destructive of employee interests” that it may be deemed proscribed without need for proof of an underlying improper motive. Labor Board v. Brown, supra, at 287; American Ship Building Co. v. Labor Board, supra, at 311. That is, some conduct carries with it “unavoidable consequences which the employer not only foresaw but which he must have intended” and thus bears “its own indicia of intent.” Labor Board v. Erie Resistor Corp., supra, at 228, 231. If the conduct in question falls within this “inherently destructive” category, the employer has the burden of explaining away, justifying or characterizing “his actions as something different than they appear on their face,” and if he fails, “an unfair labor practice charge is made out.” Id., at 228. And even if the employer does come forward with counter explanations for his conduct in this situation, the Board may nevertheless draw an inference of improper motive from the conduct itself and exercise its duty to strike the proper balance between the asserted *34business justifications and the invasion of employee rights in light of the Act and its policy. Id., at 229. On the other hand, when “the resulting harm to employee rights is . . . comparatively slight, and a substantial and legitimate business end is served, the employers’ conduct is prima facie lawful,” and an affirmative showing of improper motivation must be made. Labor Board v. Brown, supra, at 289; American Ship Building Co. v. Labor Board, supra, at 311-313.
From this review of our recent decisions, several principles of controlling importance here can be distilled. First, if it can reasonably be concluded that the employer’s discriminatory conduct was “inherently destructive” of important employee rights, no proof of an anti-union motivation is needed and the Board can find an unfair labor practice even if the employer introduces evidence that the conduct was motivated by business considerations. Second, if the adverse effect of the discriminatory conduct on employee rights is “comparatively slight,” an antiunion motivation must be proved to sustain the charge if the employer has come forward with evidence of legitimate and substantial business justifications for the conduct. Thus, in either situation, once it has been proved that the employer engaged in discriminatory conduct which could have adversely affected employee rights to some extent, the burden is upon the employer to establish that he was motivated by legitimate objectives since proof of motivation is most accessible to him.
Applying the principles to this case then, it is not necessary for us to decide the degree to which the challenged conduct might have affected employee rights. As the Court of Appeals correctly noted, the company came forward with no evidence of legitimate motives for its discriminatory conduct. 363 F. 2d, at 134. The company simply did not meet the burden of proof, and *35the Court of Appeals misconstrued the function of judicial review when it proceeded nonetheless to speculate upon what might have motivated the company. Since discriminatory conduct carrying a potential for adverse effect upon employee rights was proved and no evidence of a proper motivation appeared in the record, the Board’s conclusions were supported by substantial evidence, Universal Camera Corp. v. Labor Board, 340 U. S. 474 (1951), and should have been sustained.
The judgment of the Court of Appeals is reversed and the case is remanded with directions to enforce the Board’s order.
It is so ordered.
National Labor Relations Act, as amended, §§8 (a)(3) and (1), 61 Stat. 140-141, 29 U. S. C. §§ 158 (a)(3) and (1).
Local 26, International Brotherhood of Boilermakers, Iron Ship Builders, Blacksmiths, Forgers and Helpers, AFL-CIO.
Article VIII of the collective bargaining agreement was entitled “Vacations.” It read, in pertinent part:
“(a) Each qualified employee covered by this agreement shall be entitled after one (1) year of continuous employment, at a time agreeable to the Company, to a vacation of seven (7) consecutive days with pay for forty (40) hours at the rate of pay existing for such employee at the time of the beginning of his vacation. Each employee, after five (5) years’ continuous service, shall be entitled to a vacation of fourteen (14) consecutive days, with pay for eighty (80) hours. Any employee entitled to a vacation with pay may waive the right, if his services are needed by the employer, to such vacation during the period of this agreement, and in such cases shall be entitled to receive in lieu thereof, at the time he becomes entitled to the vacation, the amount of vacation pay such employee would otherwise have received over and above the wages received for work performed during the vacation period.
“(b) To qualify for the said vacation, it is necessary that an employee shall have worked a total of fifteen hundred twenty-five (1525) hours in the said year; any time lost, however, because of an industrial accident while employed by this Company to count as part of the qualifying time.
“(d) Employees who have served less than sixty (60) days on the next July 1 after date of employment will receive no vacation pay on that date but on the following July 1 will receive the vacation due in accordance with the above qualifying requirements, plus extra amount due in accordance with hours worked.
“(e) In case of lay-off, termination or quitting, an employee who has served more than sixty (60) days shall receive pro rata share of vacation.
“(f) All vacation pay shall be paid on Friday nearest July 1st, except as outlined in paragraph (d).”
All strikers had been replaced by October 8, 1963. After their replacement, some strikers were rehired by the company, apparently as new employees.
The complaint also charged independent violations of § 8 (a) (1). These were rejected by the Trial Examiner and by the Board.
§ 301, Labor Management Relations Act, 1947, 61 Stat. 156, 29 U. S. C. § 185.
In this Court the company apparently abandoned the argument under § 301. In any event, we agree with the Court of Appeals *31that the complaint, alleging as it did a discrimination in regard to a term or condition of employment, stated an unfair labor practice charge. The fact that the conduct complained of might also have supported an action under § 301 did not deprive the Board of jurisdiction. NLRB v. C & C Plywood Corp., 385 U. S. 421 (1967); Mastro Plastics Corp. v. Labor Board, 350 U. S. 270 (1956). Cf. Smith v. Evening News Assn., 371 U. S. 195 (1962). This, of course, is not to say that every breach of a collective bargaining agreement-may be the subject of an unfair labor practice proceeding. But when the elements of an unfair labor practice are present in a breach of contract, the injured party is not automatically deprived by § 301 of his right to proceed before the Board where his remedy may be speedier and less expensive than a lawsuit. NLRB v. C & C Plywood Corp., supra, at 429-430.
National Labor Relations Act, as amended, §2(3), 61 Stat. 137, 29 U. S. C. § 152 (3), declares:
"The term 'employee’. . . shall include any individual whose work has ceased as a consequence of, or in connection with, any current labor dispute . . . and who has not obtained any other regular and substantially equivalent employment . . . ,”