The European Commission and national governments in the euro-zone have insisted that Denmark's rejection of the euro would not jeopardise the future of the euro or hinder efforts at closer political and economic integration among the area's member states. However, the Danish 'No' risks being seen by financial markets as a wider expression of waning confidence in the currency, economists and commentators said on Friday.

Wim Duisenberg, the European Central Bank president, limited himself to saying that the ECB had taken note of the Danish verdict and would continue co-operation with Denmark's central bank.

But many commentators said the Danish 'No' raised fundamental questions about the character of the euro-zone and the path of European integration.

"The immediate problem is that Denmark's rejection of Emu [European monetary union] is being seen as a no-confidence vote in the common currency," said Carl Weinberg, chief economist at High Frequency Economics in Valhalla, New York.

By potentially making it harder for pro-euro forces in the UK and Sweden to win referendums on adopting the euro, the Danish "no" suggests that prosperous, financially disciplined northern European countries may never play a central part in European integration.

This may raise concerns in Germany and other countries by implying that the next group of euro-zone entrants after Greece - if ever there are any - will be former communist states in central and eastern Europe, such as Estonia, Hungary, Poland and Slovenia.

Their relative lack of prosperity, and their short track record of financial stability and commitment to free-market economics, may heighten suspicions in Germany and elsewhere that the euro's strength will be diluted as t he euro-zone expands.

This could cause politicians and public opinion in some existing euro-zone member states to shift in favour of closer co-operation among themselves rather than to make a priority of incorporating central and eastern Europe.

In reality, some European Union governments already seem disinclined to admit the Hungarians, Poles and others into the EU until at least 2005. Experts say their entry into the euro-zone is unlikely before 2010.

In the meantime, as they have often done in the past when confronted with a potential crisis, the core EU countries, led by France and Germany, can be expected to make a new push for closer integration among themselves.

Earlier this year, Joschka Fischer, Germany's foreign minister, sketched out his vision of a more politically integrated Europe, based on euro-zone countries and involving a European constitution, president and government with limited powers.

President Jacques Chirac of France declared himself opposed to a Eur opean government, but expressed support for the idea that a "pioneer group" of EU countries could pursue closer integration where appropriate.

Politicians in Italy, the third largest euro-zone state, have long made it clear that they see the lack of political integration as one of the factors behind the euro's weakness.