A consultative referendum on the Treaty establishing a Constitution for Europe was held in the Netherlands on 1 June 2005 to decide whether the government should ratify the proposed Constitution of the European Union. The result was a "No" vote.
The vote was the first national referendum for over two hundred years, and was not binding on the government, meaning that despite the electorate rejecting the Constitution it could theoretically still be ratified by the States-General. The government did say, however, that it would abide by a decisive result, provided turnout exceeded 30%.