Intentional or gross negligence is required for a serious breach of basic employee duties under Polish Labor Code.

The Supreme Court dismissed the appellant's cassation appeal regarding the termination of an employee's contract. The employee collected parking fees contrary to regulations but did so voluntarily to pay on behalf of a priest and later disclosed the situation to a supervisor. The court held that the termination was invalid because the employee lacked the requisite intent or gross negligence to constitute a serious breach of duties.