The Netherlands will hold a referendum on the new European constitution on 1 June, the committee organising the vote has announced.
Spain voted for the EU constitution, but turnout was low
On Sunday, Spaniards voted in favour of the constitution in a referendum, but turnout was low.
It was the first of a series of European polls on the constitutional treaty, which must be ratified by all 25 member states to come into effect.
The deadline for ratification is November 2006.
The Dutch referendum will be the first held in the Netherlands - on any issue - since it became a parliamentary democracy in 1848.
It will not be legally binding, so even if the Dutch people reject the constitution, parliament will still be able to ratify it.
However, the government has said it will abide by the vote if the result is clear.
Voters will be asked: "Are you for or against The Netherlands agreeing to the treaty to establish a constitution for Europe?"
The EU constitution is designed to streamline the EU's decision-making process after the bloc brought in 10 new members - mostly from central and eastern Europe - in May.
The EU constitution provides for the first EU president and foreign minister and incorporates certain fundamental rights into EU law.
Nine EU members have definitely said they will hold referendums, with two more countries undecided. The remainder are ratifying the treaty by a parliamentary vote.