Article 7 TEU in the Lisbon Treaty, introduced by the Treaty of Nice, can be used to suspend the voting rights of an EU member state if the other members find that it has breached human rights. The more detailed voting rules can be found in Article 354 TFEU.
Accordingly, four-fifths of the member states can warn against a breach of common principles with the support of an absolute majority of members in the European Parliament.
In 2014, this required that 23 out of 28 countries have to support a warning. Voting rights may then be suspended if approved by a qualified majority in the Council and a two-thirds majority in the European Parliament also representing an absolute majority of members.
This rule is a result of a punishment action over Austria, where the late Jörg Haider’s FPÖ-party was part of the government coalition and other EU countries disapproved of that.
See also Sanctions and Austria.