Dutch voters have decisively turned against the European constitution in their national referendum.

Their vote comes just days after France plunged Europe into months of constitutional turmoil by becoming the first country to reject the new treaty.

Some 63 per cent of voters in the Netherlands were said to be opposed to the constitution, according to the polls, with the Yes campaign garnering the support of just 37 per cent.

Turnout was also high at around 62 per cent - leaving the Dutch government with no option but to abide by the public's verdict.

Ministers had earlier suggested that a turnout of below 30 per cent would not have been considered binding.

Reports suggested that issues such as price rises following the introduction of the euro, the level of Dutch contributions to Brussels' budget, poor economic performance and fears over increased immigration contributed to the outcome.

But polling by TNS/NIPO for the Dutch TV channel RTLTV on June 1 challenges some explanations for the result.

The survey finds Turkey's accession was only an issue for a tiny two per cent of No voters.

Anti-governments protest votes were also a small factor with only five per cent directing their anger at The Hague.

The euro too was not a mobilising force against the EU – only four cent cited the single currency as the reason for a no.

The primary cause of Dutch opposition, 20 per cent, was 'loss of influence'.

And 12 per cent complained EU integration was 'too fast'.