In OP v Commune d’Ans  EUECJ C‑148/22, the Grand Chamber handed down a preliminary ruling in a Belgian case, following a request by the Tribunal du Travail de Liège.
The claimant in the proceedings before the Tribunal du Travail was an employee of the Commune who performed largely “back-office” functions without coming into contact with members of the public . In February 2021 she asked permission to wear a hijab at work . The municipal board of the Commune rejected her application and provisionally banned her from wearing “signs revealing her religious beliefs” until it had adopted general rules on the matter .
In March 2021, the municipal board amended its terms of employment by inserting a requirement of “exclusive neutrality” in the workplace: in effect, it banned all municipal workers from wearing any visible sign that might reveal their religious or philosophical beliefs, whether or not they were in contact with the public. Article 9 of those terms provided, inter alia:
“Workers have freedom of expression in accordance with the principle of neutrality, their duty of discretion and their duty to act in good faith.
Workers are required to observe the principle of neutrality, which means that they must refrain from any form of proselytising and that they are prohibited from wearing any overt sign which might reveal their ideological or philosophical affiliation or political or religious beliefs. This rule applies both to their contacts with the public and to their working relationships with hierarchical superiors and colleagues” .
Before the Tribunal du Travail Ms OP sought a declaration that her freedom of religion had been infringed, and an interdict against the individual decisions in her case and against the amendment to the municipal board’s terms of employment .
The Tribunal was doubtful whether a provision in terms of employment that imposed a requirement of “exclusive neutrality” on all workers of a public administration, even those who did not have dealings with users, was compatible with the provisions of Directive 2000/78 (the Equal Treatment Directive)  and referred the following questions to the Court of Justice:
“(1) Can Article 2(2)(a) and (b) of [Directive 2000/78] be interpreted as permitting a public administration to put in place an entirely neutral administrative environment and thus to prohibit all members of staff from wearing [signs which might reveal religious beliefs], whether or not they are in direct contact with the public?
(2) Can Article 2(2)(a) and (b) of [Directive 2000/78] be interpreted as permitting a public administration to put in place an entirely neutral administrative environment and thus to prohibit all members of staff from wearing [signs which might reveal religious beliefs], whether or not they are in direct contact with the public, even if that neutral prohibition appears mostly to affect women, and may thus constitute disguised discrimination on grounds of gender?” .
The Court noted that the concept of ‘religion’ in Article 1 of Directive 2000/78 covered both the forum internum and the forum externum and that it referred to religion and belief together, as did Article 19 TFEU and Article 21 of the Charter of Fundamental Rights. It followed that for the purposes of the application of Directive 2000/78, the terms “religion” and “belief” had to be analysed as two facets of the same single ground of discrimination . Further, the Directive applied to the public and private sectors alike – and a provision such as that in Article 9 of the municipality’s terms of employment fell within the scope of “employment and working conditions” within the meaning of Article 3(1)(c) of the Directive .
An employer’s internal rule that prohibited only the wearing of conspicuous, large-scale signs of belief – philosophical or religious in particular – in the workplace might constitute direct discrimination on grounds of religion or belief within the meaning of Article 2(2)(a) of Directive 2000/78 where that criterion was “inextricably linked to one or more specific religions or beliefs”; however, it was not apparent from the order for reference that that was the situation in this case . Conversely, such an internal rule did not constitute direct discrimination because it covered any manifestation of belief without distinction and treated all workers of the undertaking in the same way  – always provided it was applied in a general and undifferentiated way .
Therefore, unless the referring court found that Ms OP had been treated differently from other workers who had been permitted to manifest their beliefs by wearing a visible sign or in some other way and that she had suffered direct discrimination on the grounds of religion or belief, the referring court would have to examine whether the bar under Article 9 of the municipality’s terms of employment would put persons having a particular religion or belief at a particular disadvantage, effectively constituting indirect discrimination .
It was settled case-law that an employer’s internal rule prohibiting the visible wearing of any sign of belief – philosophical or religious in particular – might be a difference of treatment indirectly based on religion or belief if it was established that the apparently neutral obligation in that rule resulted in fact in persons of a particular religion or belief being put at a particular disadvantage  – but it did not amount to indirect discrimination if it was objectively justified by a legitimate aim and if the means of achieving it were appropriate and necessary 
As to whether there was a legitimate aim, the purpose of Article 9 of the municipal board’s terms of employment was to put into effect the principle of neutrality of the public service, which had its legal basis in principles of impartiality and neutrality of the State in Articles 10 and 11 of the Belgian Constitution . Each Member State had to be given a margin of discretion in how it promoted the neutrality of the public service in the workplace  – and Directive 2000/78 only established a general framework for equal treatment in employment, which left a margin of discretion to the Member States and to their infra-State bodies . The EU legislature had not itself effected the necessary reconciliation between the freedom of thought, conscience and religion and the legitimate aims that might be invoked in order to justify unequal treatment but had left it to the Member States to achieve that reconciliation . The disputed term of employment might therefore be regarded as pursuing a legitimate aim within the meaning of Article 2(2)(b)(i) of Directive 2000/78 .
If an internal rule such as that at issue in the main proceedings was not to be regarded as indirect discrimination, it had to be properly applied. In this case, the objective of “exclusive neutrality” had to be genuinely pursued in a consistent and systematic manner and the prohibition on wearing any visible sign of belief had to be limited to what was strictly necessary .
As to the issue of indirect discrimination, it was for the referring court to determine whether the municipality pursued that objective in a genuinely consistent and systematic manner towards all employees .
The legitimate objective of ensuring a policy of “exclusive neutrality” could only be effective if no visible manifestation of beliefs was allowed when employees were in contact with the public or other employees; wearing even a small sign undermined the aim allegedly pursued and therefore called into question the consistency of the policy . The referring court had to weigh up the right to freedom of thought, conscience and religion against the principle of neutrality in the public administration towards users of its services and members of its staff .
The answer to the first question was therefore that Article 2(2)(b) of Directive 2000/78 must be interpreted as meaning that an internal rule of a municipal authority prohibiting, in a general and indiscriminate manner, the members of that authority’s staff from visibly wearing in the workplace any sign revealing philosophical or religious beliefs might be justified by the desire of the authority to establish a neutral administrative environment. provided that the rule was appropriate, necessary and proportionate in the context and taking into account the various rights and interests at stake .
The referring court’s second question – whether Article 2(2)(a) and (b) of Directive 2000/78 had to be interpreted as permitting a public authority to organise an entirely neutral administrative environment by prohibiting all the members of its staff from visibly wearing signs revealing philosophical or religious beliefs where that prohibition appeared mostly to affect women and was, therefore, liable to constitute indirect discrimination on the grounds of sex – was inadmissible .
The Grand Chamber ruled as follows:
“Article 2(2)(a) of Council Directive 2000/78/EC of 27 November 2000 establishing a general framework for equal treatment in employment and occupation must be interpreted as meaning that an internal rule of a municipal authority prohibiting, in a general and indiscriminate manner, the members of that authority’s staff from visibly wearing in the workplace any sign revealing, in particular, philosophical or religious beliefs may be justified by the desire of the said authority to establish, having regard to the context in which it operates, an entirely neutral administrative environment provided that that rule is appropriate, necessary and proportionate in the light of that context and taking into account the various rights and interests at stake.”