Is an employer allowed to monitor mailboxes of works council members?

Publication date: 10 December 2019
Occasionally, the employer is allowed to monitor the mailbox of members of the works council. In that case two strict conditions have to be met: (1) There must be a substantial interest on the part of the employer, and (2) the investigation must not violate the rights of the members of the works council to a greater extent than strictly necessary for the investigation.


The Limburg District Court recently ruled on the question whether an employer is allowed to monitor mailboxes in a potential violation of the duty of confidentiality. According to the Court, the employer was not allowed to have the mailboxes of members of the works council investigated.

Duty of confidentiality

Pursuant to Article 20 of the Works Council Act (WOR), members of the works council have a statutory duty of confidentiality. This includes that they are not allowed to disclose matters and trade secrets as well as matters which they must understand to be of a confidential nature.

Prohibition against discrimination

Pursuant to Article 21 of the WOR, a prohibition against discrimination applies to works council members. This means, they must be able to perform their tasks as members of the works council in freedom and without fear for negative effects. Works council members may not be discriminated because they are involved in participation activities.

Violation of duty of confidentiality

The case before the Limburg District Court concerns the works council of the municipality of Maastricht. The works council members are thus civil servants. In addition to the duty of confidentiality pursuant to the WOR, the works councils members are therefore also subject to official secrecy.

The municipality of Maastricht has a conflict with the works council on cooperation plans with other municipalities. Draft minutes were taken of a confidential consultation with those municipalities. These draft minutes are not public, not even for the works council.  In the final minutes of the consultation certain passages from the draft minutes were left out.

The works council does however confront the mayor with one of the omitted passages from the draft minutes. In addition, the trade unions FNV and CNV were familiar with the draft minutes and published the controversial passage in a newsletter.

Employer monitors mailbox of works council member

A corporate investigations firm then investigates who leaked the draft minutes and who spread them. They also search the mailboxes of all works council members. Is that permitted?

Was the investigation necessary and in proportion?

No. The court rules:

  • The works council members were at all times transparent about how they had been provided with the passage in question. Even before the investigation it was clear that none of them was the original leak.
  • There was no reason to suspect that one of the works council members had spread the passage beyond the municipality.
  • The purpose of the investigation seems to have been more focused on the prevention of further spreading of the passages and restricting the negative effects of the draft minutes than on identifying the civil servant who leaked them. The municipality had decided in first instance not to launch an investigation and took action later “as it did not stop”.
  • The investigation is in contravention of the prohibition against discrimination of members of the works council. The works council members used the draft minutes in the context of their responsibility as works council member.

The works council’s interest of confidential exchange of information between the works council members must therefore outweigh the municipality’s interest to find out who leaked and spread the draft minutes. The investigation should have been restricted to the mailboxes of a small number of persons, including no works council members. The structure, scope and manner of the investigation are disproportionate.

When is an employer allowed to investigate the mailboxes of works council members?

The case of the Limburg District Court shows that members of the works council are not exempt from an investigation into a violation of a duty of confidentiality. However, two conditions must be met:

  1. There must be a substantial interest on the part of the employer.
  2. The investigation must not violate the rights of the members of the works council to a greater extent than strictly necessary for the investigation.

In the aforementioned case there was neither of them.


Do you have any questions about setting up a works council for your company? Do you want to learn more about you duties as an entrepreneur towards the works council or the rights and duties of the works council? Or do you have any other questions regarding works councils? Please contact us:

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