Voters in the Netherlands have overwhelmingly rejected the proposed European Union constitution.
Jubilant "No" supporters include the Socialist Party
Provisional final results indicated that 61.6% of voters said "No" to the charter and 38.4% approved it.
Prime Minister Jan Peter Balkenende, who campaigned for a "Yes" vote, said he would respect the result.
The vote deals what could be a decisive blow to the constitution, which was also rejected by French voters in a referendum at the weekend.
Mr Balkenende said he was "very disappointed" with the result but he said his government would honour the vote, which was consultative rather than legally binding.
The turnout was 62.8%, more than double the level politicians said was needed for the vote to be accepted as the public's verdict on the treaty.
With some postal ballots still to be counted, the official result is not expected until 6 June.
Mr Balkenende said that despite the result, the ratification process should continue in other countries.
Nine countries have ratified the constitution, but it needs to be approved by the EU's 25 member states to become law.
UK Foreign Secretary Jack Straw said the result of the French and Dutch votes "now raises profound questions for all of us about the future direction of Europe".
One of the leading "No" campaigners in the Netherlands, right-wing politician Geert Wilders, told reporters he had not expected such a decisive result - which exceeded poll predictions.
"I am extremely happy with it," he said.
"If you realise that two-thirds of parliament supported the constitution and two out of three people in the land are against, it means a lot is wrong in the country."
The BBC's Geraldine Coughlan in The Hague says many voters feel that Brussels has too much power and that their national politicians are not protecting them enough.
"No" supporters are also afraid of Brussels interfering in their liberal policies on soft drugs and gay marriage, they are disillusioned with the single currency, the Euro, and some disagree on rapid EU enlargement, our correspondent adds.
The centre-right government and major opposition parties had supported the draft constitution and argued that it would enhance Dutch influence in Europe.
ALREADY RATIFIED TREATY
The document was signed last year, after lengthy negotiations between members states.
It brings together for the first time the many treaties and agreements on which the EU is based. It defines the powers of the EU, stating where it can and cannot act and where the member states retain their right of veto.
It also defines the role of the EU institutions.
The constitution was rejected by 55% of French voters in a referendum on Sunday.