The European Convention on Extradition bars extradition in respect of all political offences. While it does not define the notion of political offence, it excludes from the scope of such offences the taking of the life of a head of State. The Protocol further limits the scope of such offences by excluding also war crimes and crimes against humanity.

Moreover, the Protocol supplements the provisions of the Convention that deal with the principle “ne bis in idem”, namely its Article 9, by enlarging the number of instances in which the extradition of a person is barred where that person has already been tried for the offence in respect of which the extradition claim was made.