Can my employer change my job role completely without my agreement?

Whether this is lawful largely depends on what your original employment contract actually says about the scope of your role and whether it contains any flexibility clause allowing the employer to reassign duties, since under general Maltese employment principles linked to the Employment and Industrial Relations Act, Chapter 452 of the Laws of Malta, a fundamental and unilateral change to the core nature of your role, particularly one this significant, generally requires your genuine agreement unless the contract specifically anticipated and permitted this kind of change. If your contract was specific to a marketing role with no broad reassignment clause, being moved into an entirely different administrative function without consultation or consent could potentially amount to a breach of your employment contract, and in more serious cases, depending on how it affects your standing, skills use, and career trajectory, could support a claim of constructive dismissal if you felt forced to resign as a result. Review your original contract carefully for any relevant clauses, and raise a formal written objection with your employer setting out your concerns. If unresolved, this can be raised with the Department of Industrial and Employment Relations or ultimately the Industrial Tribunal.