In a judgment dated 29 February 2016, the Supreme Court had to rule on this matter once again.

Article 171 of the programme act of 22 December 1989 contains a legal presumption according to which parttime employees are presumed to have performed their work in the context of an employment contract as a fulltime employee if the employer fails to meet his obligations in terms of displaying the part-time work schedules and its registration obligations of the derogations to these schedules.

Employers of part-time employees are obliged to keep a copy of the part-time employee's employment contract at the place where the working rules can be consulted, to inform the employees of variable part-time work schedules by displaying a notice at least five work days beforehand and to register all derogations to these parttime work schedule in a document that is provided for that purpose.

In case an employer does not meet one of these obligations, the legal presumption outlined in article 171 of the programme act of 22 December 1989 will apply. 

In a judgment dated 4 October 1999, the Supreme Court had already ruled that this legal presumption had been established for the benefit of the institutions and the authorized civil servants to prevent illegal employment and not for the benefit of the employees. Taking into account this jurisprudence by the Supreme Court, upheld today in the judgment dated 29 February 2016, employees cannot claim salary as full-time employees based on article 171 of the programme act dated 22 December 1989.

Nevertheless, it should be noted that, in its judgment, the Supreme Court rules on the scope of article 171 before its amendment by the act of 29 March 2012. Through this amendment of the act, it was added that the legal presumption was rebuttable. The explanatory statement of this amendment, however, explicitly referred to the Supreme Court's jurisprudence and hence it is explicitly confirmed that this presumption does not apply for the benefit of the employee. As such, we can depart from the principle that the current version of article 171 of the programme act of 22 December 1989 cannot be invoked by employees in order to claim a salary as a full-time employee.