The BBC's David Eades reports on Denmark's refendum campaigns

A Gallup exit poll on behalf of DR1 television indicates 56.9% had voted for the Amsterdam Treaty and 43.% against.

An exit poll by Celeste for TV2 television put the "yes" vote at 58.1% and the "no" vote at 41.9%.

Prime Minister Rasmussen has urged people to vote "yes"

Exit polls have proved inaccurate on previous polling occasions but political analysts said that despite room for error, the margins are considered big enough to ensure a victory for the "yes" side.

Officials said voter turnout seemed to be lower than in previous Danish EU polls.

Police in Copenhagen, equipped with riot-control gear are on standby should there be a repeat of street violence which followed an EU referendum "yes" vote five-years ago. No incidents were reported early in the evening.

A vital vote for the EU

Correspondents said a vote for rejection would have thrown the EU into chaos and possibly called into question Denmark's future as a member state.

Danish Prime Minister Poul Nyrup Rasmussen: "We can't isolate ourselves"

The Amsterdam Treaty consists of measures which would allow the EU to take in new members from eastern and central Europe. It also calls for the introduction of common European policies on immigration and asylum giving the EU authority over the issuing of visas, for example, in member countries.

Lutheran clergyman campaigning for "no" vote

Analysts said up to two thirds of the four-million-strong Danish electorate were wavering between their wish to be part of the EU and their intense dislike of union interference in Danish affairs.

The treaty must be ratified by all the 15 members before it can take effect.

Most EU countries have left it to their parliaments to ratify the treaty.

However, the Danes are obliged to hold a referendum because it involves sovereignty being ceded to European institutions.