In our opinion, the possibility that an employer may unilaterally impose a change to the contract is in fact excluded in the case of employees who enjoy special protection against dismissal, this being of course subject to a judicial decision to the contrary.
In fact, the only possibility for a protected employee to contest a unilateral change to his employment contract made in the legally prescribed form and time limits would be to resign; that resignation would be equivalent to dismissal and therefore make available a remedy for unfair dismissal. Changing the contract could indirectly lead to the dismissal of the protected employee, and the protection would therefore be ineffective.