4.2.8.5 Consequences of the disapplication of a legislative provision for the horizontal legal relationship

212. When on the basis of Union law a national court is obliged to disapply in horizontal proceedings a provision of national law that is incompatible with Union law, the disapplication has an impact on the horizontal legal relationship. For example, the consequence of the disapplication of a legislative provision upon which private parties have based – a part of – their legal relationship, is that this legal relationship may have no legal ground. The disapplication of the national provision may result in a number of scenarios as regards the question of how to determine the legal consequences of the disapplication of the problematic provision for the underlying horizontal legal relationship.1 As discussed in relation to the German post-Mangold cases, the disapplication of a legislative provision that is incompatible with the general principle prohibiting age discrimination and Directive 2000/78 can result in the application of a ‘reviving’ (national) provision that concretely solves the dispute between private parties after the disapplication of the problematic rule (scenario 4, discussed in no. 156 and §4.2.3). As demonstrated, the application of the ‘healthy remainders’ of a national act may result in the invalidity of a contractual clause or juridical act in the horizontal legal relationship. When disapplication of the legislative provision does not suffice for the dispute between private parties to be solved2 and when reviving, concrete European or national provisions are absent, a lacuna exists. In such an – unlikely – event, the national court or the parties to the case have to fill that lacuna and find a reasonable solution, possibly applying an open norm based on reasonableness and fairness (scenario 5).3

213. Dutch case law in which a substantive compatibility review in proceedings between private parties resulted in the disapplication of a national provision is absent.4 Assume that, along the lines of the cases of Mangold (discriminatory fixed-term contract) and Kücükdeveci (discriminatory term of notice of dismissal) a legal relationship between a private employer and an employee is based upon a national legislative provision that is incompatible with the general principle prohibiting age discrimination in Union law and therefore has to be set aside.

Most likely, the contractual discriminatory clause that was in conformity with the legislative provision that is now disapplied, is in conflict with the provisions on age discrimination in the WGBLor, additionally or alternatively, with the General Law on Equal Treatment (the Algemene Wet Gelijke Behandeling; AWGB). If the legislative provision upon which the discriminatory contractual clause was based could not be justified by the proportionality test adopted in Directive 2000/78 or its equivalent in Article 7 WGBL, it is rather unlikely that the contractual clause can be justified and would therefore be an accepted exception to the prohibition of age discrimination.5

214. In cases in which the termination of the employment contract would be in conflict with the prohibition of age discrimination, Article 11 WGBL determines that such termination would be voidable by a request thereto by the employee within two months after the respective termination.6 However, as indicated above, neither Mangold nor Kücükdeveci concerned the discriminatory termination of the employment contract7. Therefore, Article 11 WGBL would not apply. As regards a Dutch variation of the Mangold case, it is likely that a national court would deploy Article 13 WGBL to deem the discriminatory contractual clause limiting the duration of the employment contract to be null and void. The legal consequences of nullity on the basis of Article 3:40BW are discussed in §3.2.5.3. The same applies to the nullity on the basis of Article 13 WGBL. In essence: the nullity has retroactive effect, which means that the clause is considered to have never existed. Further, in principle the nullity would concern partial nullity (Article 3:41BW): only the discriminatory clause is null and void, and not the entire employment contract or parts of it that are not in conflict with the prohibition of age discrimination.8 In a concrete case this would mean that the clause on the basis of which the duration of the employment contract was limited, is null and void and that, as a consequence, the employment contract is changed into an indefinite employment contract.9

215. Occasionally, the incompatibility of a contractual clause with remaining legislation can be easily repaired by converting the respective clause into a valid clause. Article 3:42BW allows the court to convert a clause in order to escape its nullity.10 Conversion can either be based on a concrete statutory provision or on the open norm of reasonableness and fairness, more specifically the supplementary function thereof in Article 6:2(1) BW and Article 6:248(1) BW.11 In the field of employment contracts, national courts must however show a certain amount of restraint in applying the mechanism of conversion.12

216. The Kücükdeveci case did not concern a contractual clause. The employer simply applied a term of notice on the basis of a legislative provision. In the hypothetical Dutch variation to this case, the WGBLdoes not provide for a solution. Article 7:672(2) BW, the general provision on the calculation of the term of notice for dismissal termination of employment contracts, applies ex post facto to the case at hand. Consequently, the employer will have to comply with that period and pay an amount equating the monthly salary for the period added.