The Ioannina compromise takes its name from an informal meeting of foreign ministers in the Greek city of Ioannina on 29 March 1994. At the meeting the Council adopted a decision concerning the specific question of qualified majority voting in an enlarged 16-member Union. The decision was later adjusted in the light of Norway's decision not to join. The resulting compromise laid down that if members of the Council representing between 23 votes (the old blocking minority threshold) and 26 votes (the new blocking minority threshold) demonstrated their intention to oppose the taking of a decision by the Council by qualified majority, the Council would do all within its power, within a reasonable space of time, to reach a satisfactory solution that could be adopted by at least 68 votes out of 87.
The Lisbon Treaty (Article 16 of the Treaty on European Union) introduces a new definition of the rule of qualified majority which shall apply from 1 November 2014 onwards. However, between that date and 31 March 2017, it will be possible for each Member State to require the previous weighting rules to be applied. It will also be possible to make the “Ioannina compromise” applicable. This will enable countries representing at least three quarters of the population of the Union or at least three quarters of the number of Member States required to constitute a blocking minority, to oppose the vote for an act by the Council by qualified majority in order to try to find a solution within a reasonable space of time. From 1 April 2017, the new rule of qualified majority shall become compulsory. The activating percentage of the “Ioannina compromise” shall be reduced to at least 55% of the population of the Union or at least 55% of the number of Member States required to constitute a blocking minority.