I want to know the answer to the following question:
Will mainstream political parties not cooperate towards outsider parties if they are too extream?
All the background I'm provided with is that "Furthermore, in the case of far-right, far-left and regionalism parties in the national parliaments of much of the European Union, mainstream political parties may form an informal cordon sanitarian which applies a policy of non-cooperation towards those "Outsider Parties" present in the legislature which are viewed as 'anti-system' or otherwise unacceptable for government.". Is that enough to answer the question?
Answer: yes