The European Parliament election, 2004 was the United Kingdom's part of the wider European Parliament election, 2004 which was held between 10 and 13 June 2004 in the 25 member states of the European Union. The United Kingdom's part of this election was held on Thursday 10 June 2004. The election also coincided with the 2004 local elections and the London Assembly and mayoral elections. In total, 78 Members of the European Parliament were elected from the United Kingdom using proportional representation.