Opinion for the Court filed by Circuit Judge WALD.
Petitioner, Consolidated Freightways (“Consolidated”), seeks review of a decision of the National Labor Relations Board (“NLRB” or “Board”), 253 N.L.R.B. No. 137 (1981), ordering it to reinstate a former employee, Charles Hennessey, with full backpay. Because we find that the Board failed to address petitioner’s argument that Hennessey’s refusal of a prior reinstatement offer tolled petitioner’s backpay liability, we remand for further proceedings.
I. Factual Background
Consolidated discharged Hennessey on March 22, 1979, after Hennessey refused to drive a tractor with faulty lights. Hennes-sey filed a grievance challenging his dis *792 charge. His case was brought before the Joint State Committee (“Committee”), an arbitration committee composed of three members of the union and three representatives of the trucking industry. 1 On May 1, 1979, the Committee ordered that Hennes-sey be reinstated with full seniority and health and welfare benefits, but with a final warning letter and no backpay. Consolidated proceeded to put Hennessey back on “the board” for work. Joint Appendix (“J.A.”) 15. Hennessey, however, did not return to work, explaining to a supervisor that he would not return without backpay, Record (“R.”) 61. 2
On July 11, 1979, Hennessey filed a charge with the NLRB asserting that he had been discharged for protected concerted activities in violation of section 8(a)(1) of the National Labor Relations Act, 29 U.S.C. § 158(a)(1). The Administrative Law Judge (ALJ) refused to defer to the Committee’s award, 3 noting that the award “required Hennessey to be reinstated but in effect to be under the gun of a warning letter.” J.A. 15. Although the ALJ made no specific findings regarding the effect of a warning letter, his conclusion appears to be based on the terms of the labor agreement between Consolidated and Local Union No. 710 of the International Brotherhood of Teamsters, Chauffeurs, Warehouse-men and Helpers of America. That agreement provides that no employee may be discharged or suspended before receiving at least one warning notice regarding the particular complaint against him. See Exhibit 6C-5 at 79-80. The ALJ concluded that a reinstatement offer conditioned on receipt of such a letter failed to remedy the alleged unfair labor practice and that, consequently, the Board need not defer to the arbitrator’s award. 4
On the substantive merits of Hennessey’s charge, the AU found that Hennessey’s refusal to drive the tractor was based on a reasоnable belief that to do otherwise would be unsafe under legislatively approved safety standards. Despite the fact that Hennessey was acting alone, the ALJ concluded that absent any evidence that other employees disavowed Hennessey’s ac *793 tions, Hennessey’s conduct constituted protected concerted activity, 5 J.A. 13, and his discharge was therefore a violation of § 8(a)(1) of the National Labor Relations Act, 29 U.S.C. § 158(a)(1). J.A. 16. As a remedy, the ALJ ordered that Hennessey be reinstated with full backpay up to the date of a valid offer of reinstatement. J.Á. 13. Consolidated appealed to the Board, arguing that its offer of reinstatement following the arbitrator’s award tolled its backpay liability and discharged its obligation to offer Hennessey reinstatement. The Board sustained the ALJ’s order. 6
II. Analysis
Consolidated does not challenge the Board’s finding that it violated § 8(a)(1) by discharging Hennessey, Brief for Petitioner 25; nor does it challenge the Board’s refusal to defer to the arbitrator’s award. Id. Instead, Consolidated argues that by offering Hennessey reinstatement in accordance with the terms of the arbitrator’s decision it discharged its legal obligation and stopped the aсcumulation of backpay liability. In addition, Consolidated argues that since Hennessey refused reinstatement for an admittedly invalid reason (the denial of back-pay), Hennessey is entitled to neither a second offer of reinstatement nor backpay which might otherwise have accrued after that refusal. In response, the Board argues that Consolidated’s offer of reinstatement was invalid because it was conditioned on accepting a final warning letter. Such a letter, it contends, would have subjected Hennessey to continued discrimination for exercising protected rights. Sinсe this offer was invalid, the Board further argues that there is no need to inquire into Hen-nessey’s reasons for refusing to accept it. Finally, the Board contends that the question whether Hennessey refused reinstatement for invalid reasons was not raised before the Board and therefore cannot be raised on appeal.
A. The Issues Before the Board
As an initial matter, we must consider whether Consolidated’s argument that Hennessey improperly refused reinstatement is barred by section 10(e) of the National Labor Relations Act, 29 U.S.C. § 160(e). Section 10(e) provides that:
No objection that has not been urged before the Bоard, its member, agent, or agency, shall be considered by the court, unless the failure or neglect to urge such objection shall be excused because of extraordinary circumstances.
29 U.S.C. § 160(e). This section furthers “the salutary policy ... of affording the Board opportunity to consider on the merits questions to be urged on review of its order.”
Marshall Field & Co. v. N.L.R.B.,
In this case, we find that Consolidated’s objections before the Board were sufficient to permit it to argue on appeal that Hennessey’s improper grounds for refusing reinstatement relieved Consolidated of any obligation to make a subsequent reinstatement offer and, correlatively, tolled Consolidated’s backpay liability. In its exceptions to the ALJ’s recommendations, Consolidated specifically objected to his failure to find “[tjhat the Charging Party refused the May 1 1979 offer of reinstatement because it did not include an offer of backpay. ...” Respondent’s Exceptions to the Decision and Recommended Order of Administrative Law Judge Dated July 30,1980 3 (emphasis added). In addition, Consolidated discussed Hennessey’s grounds for refusing the reinstatement offer in its brief to the Board. It argued that “the fact that the warning letter did not enter into Hennessey’s mind when he rejected [Consolidated’s] unconditional offer of reinstatement” was “of great significance,” and that it was “anomalous” for the ALJ to “void an otherwise valid offer of reinstatement because of what he perceived as a ‘condition’ to reinstatement when that alleged ‘condition’ (the letter) never entered the mind of the Charging Party when he rejected the offer.” See Respondent’s Brief in Support of its Exceptions to the Decision and Recommended Order of the Administrative Law Judge dated July 30, 1980 16-17.
The Board argues that this discussion was insufficient to satisfy section 10(e) because it appeаred as part of Consolidated’s argument that its offer was unconditional and was not accompanied by citations to any of the authorities that Consolidated is relying on in this appeal. Brief for Respondent 23. The General Counsel’s own brief, however, set the issue of Hennessey’s grounds for refusal in the proper context. The General Counsel argued that “the fact that Hennes-sey declined the offer [should not] relieve
*795
[Consolidated] of its obligation to tender a valid offer of reinstatement.” Answering Brief in Response to Respondent’s Exceptions to the Decision and Recommendеd Order of Administrative Law Judge Dated July 30, 1980 6-7. He then proceeded to quote a recent Board opinion in which the Board ruled that an employer who had been ordered to reinstate certain employees was not excused from that order by letters from these employees “ ‘to the effect that they did not wish to return to [his] employ.’ ”
Id. at
7
(quoting Leroy W. Craw,
Having discharged Hennessey for unlawful reasons, it was and is Respondent’s responsibility to remedy the unfair labоr practices. The facts indicate that Hen-nessey made statements indicating that his reason for not going back to work was the lack of backpay in the award. Respondent’s liability to reinstate Hennes-sey, however, continues until a proper offer of reinstatement is made.
J.A. 16. In the light of both Consolidated’s emphasis on the significance of Hennessey’s grounds for refusing Consolidated’s offer, and the ALJ and General Counsel’s arguments that those grounds were of no importance to the disposition of this case, we find that the Board had adequate notice of the issue raised here on аppeal.
B. Hennessey's Refusal of Consolidated’s Offer
Although the question whether Hennes-sey improperly refused an offer of reinstatement was before the Board, the Board did not address that question in its opinion, relying instead on the findings and conclusions of the ALJ. 8 The ALJ, however, had simply assumed that Hennessey’s reasons for refusing Consolidated’s offer were irrelevant to the determination of Consolidated’s backpay liability. Consolidated argues that this assumption is not in keeping with Board precedent and that by failing to distinguish or overrule cases that require an inquiry into an employee’s grounds for refusing reinstatement, the Board has acted аrbitrarily. Because we find that the Board’s policy as to unjustified refusals of reinstatement offers remains unexplained, we remand this issue to the Board to reconsider its opinion.
In stating that Hennessey’s reasons for not going back to work were of no importance, the ALJ failed to take account of Board precedent that emphasizes the actual reasons why an employee refuses an offer of reinstatement even when the validity of the offer itself is challenged. In
Research Designing Service, Inc.,
In ignoring the issue of Hennessey’s reasons for declining Consolidated’s offer, the Board may have relied on a recent case cited in the General Counsel’s brief. Brief to the National Labor Relations Board In Answer To Respondent’s Exceptions Thereto 7. The question in
Leroy W. Craw,
Although Leroy W. Craw could signal a change of Board policy abandoning any inquiry into the reasons why a conditional offer is refused, the case might also be reconcilable with earlier Board precedent. The offer in Leroy W. Craw plainly stated its invalid conditions and employees who rejected that offer because they had procured “better jobs” might well have gone back to the company if faced with a valid offer. Thus, the ALJ’s conclusion may be seen as consistent with an inquiry into whether an employee rejected an offer of reinstatement for reasons other than its invalid conditions.
In contrast, Hennessey’s refusal of Consolidated’s offer would seem an appropriate case for applying the rule of
Research Designing
and L.
Ronney.
The testimony regarding Hennessey’s reason for refusing Consolidated’s offer was uncontradicted; he would not return without back-pay. R. 61. That reason was not valid under Board precedent because it violated Hennessey’s duty to mitigate his damages.
See National Screen Products Co.,
In view of the Board’s failure to reconcile its decision in this case with its precedent, and its failure to explain its reasons for abandoning any inquiry into the reasons why a conditional offer is refused, we have no choice but to remand this case to the Board to explicate the circumstances, if any, under which an inquiry into whether an employee would have rejected a valid offer of reinstatement is proper.
16
See generally Road Sprinkler Fitters Local No. 669 v. N.L.R.B.,
Remanded.
Notes
. The parties to this action stipulated that the “entire grievance and arbitration procedure was fair and regular in all respects.” Joint Appendix (J.A.) 15.
. This explanation came several days after Hennessey was told that he had his job back. According to the ALJ’s findings, the union steward spoke to Hennessey immediately after the arbitrator rendered its decision, explaining that he could probably resume work that same night. J.A. 15; see Record (“R.”) at 187. Hen-nessey’s testimony, however, indicates that he was somewhat confused about when he could return to work. Although he received two phone calls to return to work between May 1, 1979, the date of the arbitrator’s award, and May 4, 1979, Hennessey testified that he expected to receive “something in writing stating [that he] had been reinstated.” R. 61. When the Operations Manager, Charles Schmalz, phoned Hennessey on May 4 to ask him if he was planning to return to work, this confusion was cleared up. But when аsked whether he would resume work, Hennessey stated that he would not, explaining that “under the conditions that I didn’t get the money that I deserved ... I didn’t see that I could come back to work.” R. 61. Hennessey testified that he then agreed to send in a letter of resignation, but never did so. R. 61. Consolidated subsequently sent Hennessey a letter acknowledging his resignation, to which Hennessey did not respond. R. 262.
. The Board’s policy of deference to arbitration awards was announced in
Spielberg Mfg. Co.,
. The ALJ suggested that his decision not to defer to the arbitrator’s award was based, in part, on its failure to include backpay. J.A. 15. On appeal, the Board agreed that the warning letter placed an invalid condition on reinstatement, but reaffirmed its previous holding that an offer of reinstatement is valid even if it fails to include baсkpay. J.A. 21. Since we find that the Board should have considered Hennes-sey’s reasons for rejecting Consolidated’s offer, we do not reach the question whether the offer was in fact conditional.
. Consolidated suggests that our recent decision in
Kohls v. N.L.R.B.,
. The Board noted that Consolidated did not take exception to the ALJ’s refusal to defer to the arbitrator’s award or to his ruling that Consolidated had committed аn unfair labor practice by discharging Hennessey for engaging in protected concerted activity. J.A. 20.
. The close factual inquiry required by this standard is illustrated by our decision in
Burinskas
v.
N.L.R.B.,
. See p. 9 supra.
. The Board also reversed the trial examiner’s order with regard to another employee who had refused reinstatement becausе “he was working longer hours and making more money at his current job.” Research Designing Service, Inc.,
. With regard to another employee, the Board in
L. Ronney
found that there was sufficient evidence that he would have accepted the employer’s offer had it not been conditional. L. Ronney & Sons Furniture Mfg. Co.,
. Cases involving time conditions also support an inquiry into the employee’s reasons for rejecting an offer of reinstatement. Time conditions on acceptance are somewhat different from conditions that go to the nature of an employee’s work becаuse they do not prevent the employee, if he accepts in a timely manner, from being made whole. Time conditions are therefore not really conditions on the offer, but rather limitations on the time for acceptance. As such, they must comport with the employee’s “fundamental right to a reasonable time to consider whether to return.”
Penco Enterprises, Inc.,
. In
Leroy W. Craw,
. On appeal, the Board adopted the findings and conclusions of the Administrative Law Judge.
See Leroy W. Craw,
. This testimony was given during questioning by the ALJ:
Judge Stone: ... As best you can [,] tell me exactly what [the Joint State Committee] told you the results of the grievance hearing were?
Hennessey: Well, sir, they told me that the discharge had been overturned. That the pay claim had been denied. The company was responsible to pick up my pension and health and welfare benefits with full seniority rights.
Judge Stone: Now, was there any thing else said to you at all?
Hennessey: No, sir, not that I remember. Judge Stone: Did they give you anything in writing?
Hennessey: No, sir. I picked up a copy of the results of the grievance about five weeks later. And it was at that time when I finally realized there had also been a thing where the discharge had been reduced to a final warning letter.
Judge Stone: . .. Now, did you know at the time the griеvance hearing was over, when you were orally told, did you know at that time there was anything about a warning? Hennessey: No, sir, I did not.
R. 99-100.
The ALJ did not make any findings regarding Hennessey’s awareness of the final warning letter, presumably because of his conclusion that Hennessey’s reason for refusing Consolidated’s offer of reinstatement were of no importance.
. Consolidated also argues that its good faith reliance on the arbitration award provides an independent basis for overturning the Board’s decision. It suggests that even in cases in which the Board properly refuses to defer to an arbitratоr’s award, the Board should nonetheless look to the award to determine the interim rights of the parties. Thus, it argues, Hennes-sey should have been required to accept employment as conditioned by the arbitrator’s decree, even though the Board ultimately ruled *798 that the arbitrator’s award contained an illegal condition.
Because we are remanding this case to the Board to reconsider the significance of Hennessey’s motives for refusing Consolidated’s offer, we need not reach the question whether Consolidated’s good faith reliance on the arbitrator’s decree, in itself, would be sufficient to toll backpay liability. We note, howеver, that resolution of this question depends on whether the Board could properly further the strong national policy in favor of private settlement of labor disputes without abdicating its responsibility to remedy violations of national labor law.
See Local Union No. 2188, International Bth’d of Elec. Workers v. N.L.R.B.,
. We are especially hesitant to decide this question without the benefit of the Board’s reasoning in the light of contradictory signals from the Board regarding the analogous situation in which an employer who has made no reinstatement offer at all seeks to reduce his backpay liability by proving that an offer would have been rejected.
Compare Roadway Express, Inc.,
254 N.L.R.B. No. 26, 48-49 (1981) (evidence that employee intended to quit does not obviate need for a valid offer of reinstatement)
and Lyman Steel Co.,
