In some parts of Europe, the Convention and its resulting constitution received little public attention until December 2003, when European heads of state met (14 December) to finalise the document. Elsewhere, the text was the subject of some controversy, during 2003 in the United Kingdom, where its opponents see it as the start of moves towards a federal European superstate. Several UK groups and political parties, including the official opposition Conservative Party, have demanded a national referendum on whether to ratify the treaty, calls that have so far been resisted by the Government.