An employee who does not agree with the change imposed by his employer must bring proceedings for annulment “within a reasonable period” otherwise his action will be time-barred.
If the employee has not acted immediately, it will not be possible to infer from his silence, otherwise than in exceptional circumstances, that he has tacitly accepted the measures taken.
What constitutes “a reasonable period” will be assessed in the absolute discretion of the courts.
In a particular case, it was held in the case law that an employee should have taken action within the year following the substantial change to his contract and that his prolonged silence does not allow tacit acceptance to be inferred.
A period of 3 years was held to be unreasonable where the employee continued to work for 3 years under the new working conditions; the Court inferred from this that the employee had, after several years, agreed to the change to his employment contract.