Euro
Denmark and the United Kingdom received opt-outs from the Maastricht Treaty and do not have to join the euro until they choose to do so; Sweden has not received an opt-out, yet refuses to join for now, as well. Two referendums have been held on the issue up to now, both of which failed:
- Denmark - 53.2% against, turnout 87.6% on 28 September 2000
- Sweden - 56.1% against, turnout 81.2% on 14 September 2003
Read more about this topic: Referendums Related To The European Union