(21)Preventing contagion to avoid a significant adverse effect on the financial system is a further resolution objective which may justify an exclusion from the application of the bail-in tool. In any event, exclusion on this basis should only take place where it is strictly necessary and proportionate, but also where the contagion is so severe that it would be widespread and severely disrupt the functioning of financial markets in a manner that could cause a serious disturbance to the economy of a Member State or of the Union.