Would undermine national sovereignty  Separating the European Parliament elections from the individual countries of Europe is clearly a challenge to national sovereignty. Each member state should be able to decide how it conducts its elections (within a certain general framework), what parties can compete in those elections, the rules governing campaigning etc. The basis of the European Union is what is agreed between the member states by the members of the European Council. In the treaty of Lisbon it was agreed that “Representation of citizens shall be degressively proportional, with a minimum threshold of six members per Member State. No Member State shall be allocated more than ninety-six seats.” [1] A change to a single constituency would break this provision that has been agreed by the nation states.  [1] ‘Article 9 A’, Official Journal of the European Union, 17 December 2007,  C306/17