Of the ten Member States that joined the European Union on 1 May 2004, nine held a referendum prior to their accession. Cyprus did not hold a referendum. The Cypriot House of Representatives unanimously approved the Accession Treaty. In Bulgaria and Romania, which joined the European Union on 1 January 2007, the Accession Treaty was approved by parliamentary process in both countries.
Each of the Union's current Member States were represented at, and fully participated in, the work of the European Convention which met from February 2002 and which laid the groundwork for the draft Constitutional Treaty. The Convention comprised of more than 200 representatives from the Member States, national parliaments and the EU institutions.
The essential balance and substance of the draft Constitutional Treaty, which followed from the work of this representative Convention, is preserved in the Reform Treaty signed on 13 December. As a result, and given also of course the debates and reviews in the Parliaments of Member States by their elected representatives on the Reform Treaty, current Member States and their citizens have been facilitated in taking into account the principal developments and issues now incorporated in the Reform Treaty.