When a high court declares and action of the executive ultra-vires, it means that

When a high court declares an action of the executive ultra-vires, it means that the action is illegal and of no effect. The term ultra-vires means "beyond powers." Therefore, the court has determined that the executive has acted beyond its legal powers and, as a result, the action is deemed illegal and invalid. This decision requires the executive to reconsider the action or find an alternative solution that is within its legal powers. It does not necessarily mean that a vote of no confidence has been passed on the executive by the judiciary, as that is a separate political process.