Regarding the burden of proof in Spanish Labor Law
When filing a Lawsuit against a company on behalf of the employee due to a violation of the employer of fundamental (constitutional) rights, something very important has to be taking into consideration regarding the burden of proof. And that is basically that the plaintiff must provide reasonable evidence that the contested act may have injured the corresponding fundamental rights.
Therefore the plaintiff would have to provide in the corresponding filing the indications of such business behavior or decision that caused the claimed violation, as it is expressed in our Constitutional Court precedents in ruling such as SSTC 171/2003, 171/2005, where we should highlight the following extract:
“It should be remembered, once again, that since STC 38/1981, of November 23rd, the doctrine of this Court has been highlighting the importance of the rules of distribution of the burden of proof to achieve the effectiveness of the protection of fundamental rights in the field of labor relations. In this sense, we have pointed out that when it is alleged that a certain measure actually covers up a conduct that is harmful to fundamental rights, the burden of proving that his action is due to reasonable reasons, unrelated to any intention that violates a fundamental right, although in order to impose the burden of proof expressed, the plaintiff must provide reasonable evidence of the contested act that may have injured her/his fundamental rights."