According to article 88 of law 4808 (vol. A' 101/19.06.2021) on the protection of trade union action, employers, persons acting on their behalf and any third party are prohibited from carrying out any act or omission that tends to obstruct the exercise of trade union rights of employees, and in particular:
a) to influence employees, regarding the establishment or non-establishment of a trade union organization,
b) to impose or impede in any way or means the membership of employees in a certain trade union organization,
c) require employees to declare their membership, non-membership or withdrawal from a trade union organization,
d) to support a certain trade union organization financially or by other means,
e) to intervene in any way in the administration, operation and action of trade union organizations,
f) to treat employees with favor or disfavor, depending on their membership in a certain trade union organization.