Can a union be held liable for failing to accommodate an employee's religious beliefs?

In Renaud v. Central Okanagan School District No. 23, 1992 CanLII 81 (SCC), [1992] 2 S.C.R. 970, [1992] 6 W.W.R. 193 [16 C.H.R.R. D/425], Mr. Justice Sopinka stated as follows at p. 207 [C.H.R.R. § 35–37, 39–40]: As I have previously observed, the duty to accommodate only arises if a union is party to discrimination. It may become a party in two ways. First, it may cause or contribute to the discrimination in the first instance by participating in the formulation of the work rule that has the discriminatory effect on the complainant. This will generally be the case if the rule is a provision in the collective agreement. It has to be assumed that all provisions are formulated jointly by the parties and that they bear responsibility equally for their effect on employees ... Second, a union may be liable for failure to accommodate the religious beliefs of an employee notwithstanding that it did not participate in the formulation or application of a discriminatory rule or practise. This may occur if the union impedes the reasonable efforts of an employer to accommodate. In this situation it will be known that some condition of employment is operating in a manner that discriminates on religious grounds against an employee and the employer is seeking to remove or alleviate the discriminatory effect. If reasonable accommodation is only possible with the union's cooperation and the union blocks the employer's efforts to remove or alleviate the discriminatory effect, it becomes a party to the discrimination. In these circumstances, the union, while not initially a party to the discriminatory conduct and having no initial duty to accommodate, incurs a duty not to contribute to the continuation of discrimination... While a general definition of a duty to accommodate is the same irrespective of which of the two ways it arises, the application of the duty will vary. A union which is liable as a co-discriminator with the employer shares a joint responsibility with the employer to seek to accommodate the employee. If nothing is done both are equally liable. Nevertheless, account must be taken of the fact that ordinarily the employer, who has charge of the workplace, will be in the better position to formulate accommodations. The employer, therefore, can be expected to initiate the process. The employer must take steps that are reasonable. If the proposed measure is one that is least expensive or disruptive to the employer but disruptive of the collective agreement or otherwise affects the rights of other employees, then this will usually result in the finding that the employer failed to take reasonable measures to accommodate and the union did not act unreasonably in refusing to consent... In the second type of situation in which the union is not initially a contributing cause of the discrimination but by failing to cooperate impedes a reasonable accommodation, the employer must canvass other methods of accommodation before the union can be expected to assist in finding or implementing a solution. The union's duty arises only when its involvement is required to make accommodation possible and no other reasonable other alternative resolution of the matter has been found or could reasonably have been found.