OPINION OF THE COURT
Wallach, J. P.This proceeding challenges an administrative determination that petitioner Transit Authority (TA) unlawfully discriminated against complainant Mary Myers by failing to accommodate her observance of the Sabbath. The matter was transferred to this Court for disposition in the first instance, under Executive Law § 298 and 22 NYCRR 202.57 (c).
Myers is a Seventh Day Adventist who abstains from work on the Sabbath, from sundown on Friday to sundown on Saturday. In June 1988 she was hired by the TA as a bus operator trainee. After completing six weeks of Monday-through-Friday training, she selected the East New York Depot as her assignment, and Wednesday and Thursday as her regular days off. Her first choice was Friday and Saturday, but those more popular off-days were already preempted by *222employees more senior to her. When Myers presented a request for special consideration on religious grounds, petitioner Transport Workers Union (TWU) objected to any such accommodation on the ground that it would violate the seniority rules in the collective bargaining agreement.
On several occasions in September and October, the TA felt obliged to issue warning slips for Myers’ failure to show up for work on Fridays and Saturdays. The TWU refused to waive the seniority rule in order to accommodate Myers’ religious observance, and the TA declined to contest the issue with the Union in the interest of maintaining harmony in the workplace. Myers’ employment was terminated on October 10, 1988.
A 219-page collective bargaining agreement, signed in April 1988, governed the labor relations between the TA and its more than 33,000 employees, as well as the TWU’s responsibilities, during the SVz months of Myers’ employment. Embedded in that agreement is the protection of the earned seniority rights of all employees, and neither the TA nor the Union is empowered to dilute those contractual rights. Entitlements of senior service include the right to preferential "picks” to escape weekend duty assignments, as well as vacation and holiday choices. Since the TA operates its surface mass transit service on a seven-day, 24-hour basis, practice dictates that weekend service must be staffed almost entirely by those junior in service. The uncontradicted testimony at the hearing before respondent Division of Human Rights was that relief from weekend assignments was heavily preferred by TA employees, especially those with families, and that this "perk” was earned only by years of service.
Because the Division’s order completely failed to take account of the foregoing realities prevailing at Myers’ own workplace as well as at bus depots throughout the City, and utterly ignored the applicable provisions of the collective bargaining agreement, it was not based on substantial evidence. And in ignoring settled law, it was clearly arbitrary and must be annulled.
At the outset, we note the Division’s jurisdiction over both the TA, as her employer (Executive Law § 296 [10]), and the TWU, as her labor organization (§ 296 [1] [c]). However, an employer need not make accommodation for a Sabbath observer where such would be "clearly prohibited * * * by nondiscriminatory provisions of its collective bargaining agree*223ment” (Matter of Schweizer Aircraft Corp. v State Div. of Human Rights, 48 NY2d 294, 299). In Trans World Airlines v Hardison (432 US 63), the Supreme Court held that a collective bargaining agreement which rendered seniority rights superior to accommodation for religious observance was nondiscriminatory. Indeed, the Court specifically held that where the employer and union had agreed to such a seniority system, the employer had no right to contravene those rules unilaterally.
In response to the concerns expressed in the concurring opinion suggesting that the law should require employers to make "reasonable efforts * * * to accommodate [religious] belief’, we would only note that the TA, in the spirit of Matter of Schweizer Aircraft Corp. v State Div. of Human Rights (supra), did make a sincere effort at the outset to accommodate Myers’ special needs. The Commissioner found that the TA initially took no action against Myers for missing work on Saturdays, and that the TA supervisor and the TWU representative had tried to work out a schedule which would allow her to be off during her Sabbath. But as she made the transition, in late summer, from trainee to fully qualified driver, the Union became less cooperative when it became clear to it that such accommodation at Myers’ chosen duty location would conflict with the earned rights of employees more senior to her.
The courts are not free to downgrade the importance of union seniority rights. At the administrative hearing, one Union witness, Bill Bracken, who had been a bus operator for 16 years, testified as follows with respect to the significance of those rights to employees who have earned them through longevity of service:
"Seniority is really all that they have on the job, that they got nothing else, and without seniority you got nothing.
"We’ve got people that went through the mill and they’re now just beginning to see the light. They are able to be home with their kids on the weekend and everybody, go through that period.
"See, unfortunately, my kids—I didn’t even grow up with my kids. Unfortunately, you know, that’s the nature of the job, you know.”
Since the outcome of this case is wholly governed by prevailing law, the suggestion in the concurring opinion that the present balance of competing interests "invites intolerable *224discriminatory consequences through rigid adherence to contractual provisions”, and may "impose de facto discrimination”, is at best gratuitous. Such language, while affording great deference to the Free Exercise Clause of the First Amendment, ignores the preceding prohibition of equal force that "Congress shall make no law respecting an establishment of religion”.
Simply put, to find the proper balance between the Free Exercise Clause and the Establishment Clause may not always be easy (see, Sherbert v Verner, 374 US 398 [esp concurring opn by Stewart, J., at 416]). Nevertheless, it is important to recognize that true religious liberty is damaged, not only where a penalty is attached to religious observance, but also where the State acts to promote the welfare of one religious group ahead of another. The Constitution firmly condemns both courses with the same neutral hand.
In view of the foregoing, it is unnecessary to reach the other contentions of the parties.
Accordingly, upon the transfer order of Supreme Court, New York County (Carmen Beauchamp Ciparick, J.), entered on or about April 21, 1994, the order of the State Division of Human Rights, dated March 31, 1993, which found that petitioners had discriminated against complainant Mary Myers by failing to accommodate her observance of the Sabbath and terminating her employment in violation of the Human Rights Law, and awarded her reinstatement, back pay and $50,000 as compensation for mental anguish, should be annulled, without costs.