Hans and Klaus Haekkerup, two middle-aged Danish brothers, typify Denmark's schizoid euro stance. Hans, the elder, is convinced that membership of the euro zone would safeguard jobs, shelter the economy from external shocks and give Danish policymakers the opportunity to help shape Europe's future.

His younger brother disagrees. Klaus Haekkerup is concerned about the negative impact the sacrifice of monetary control could make on the democratic process and the welfare state.

Such views are not unusual in Denmark. It is who the brothers are that lends them interest. The Haekkerup family is one of Denmark's greatest political dynasties. During the last 100 years, family members from four successive generations have represented the Social Democratic Party in parliament.

Hans Haekkerup is Denmark's Minister of Defence, while Klaus Haekkerup is one of only two Social Democratic MPs who are campaigning to keep the euro out of Denmark.

Danish voters will issue their verdict on September 28th. But with less than three weeks to go to polling day, the referendum outcome is far from certain. Recent opinion polls indicate a slight lead for euro supporters. A Gallup poll published yesterday put the Yes side ahead at 42 per cent to 41 per cent.

However, the standard opinion poll 3 per cent margin of error and the fact that around one-fifth of voters remain undecided means this referendum is still anybody's race. When it comes to the euro, Danish society is split into two almost equal camps.

The difference of opinion crosses occupation, class and gender divides. Most wealthy Danes are for, but some are against. The opposite is true for those on low incomes. This referendum is also unravelling the normal patterns of political behaviour. Voters are dropping their traditional party allegiances, disregarding the advice of the political elite and following their own convictions and consciences.

In Denmark this is nothing new. Danes have always been among the most ambivalent of Europeans. The country entered the EEC in 1973 with Ireland and Britain but did so only to safeguard its lucrative bacon exports to the UK.

Four other Danish referendums on Europe have taken place in the interim. The 1986 ballot on the single market was passed by a narrow 56 per cent to 43 per cent margin. But in 1992 Danish voters rocked the European Union to its core by rejecting the Maastricht Treaty on stronger European integration by a slim margin.

This decision threatened the whole future of European co-operation as the treaty was legally inoperative without the Danish government's signature. Denmark's snub to Europe triggered a dramatic sequence of events.

Financial markets went into convulsions. Several European currencies were devalued and the European Monetary System, the forerunner for monetary union, fell apart. Order was only restored a year later when the Danish government persuaded voters to accept a diluted version of the Maastricht Treaty with opt-outs from economic and monetary union and three other key areas.

Little has changed in Denmark in the last seven years. The forces of the establishment - big business, mainstream politicians and most trade unions - are still fighting hard and spending lavishly in an attempt to persuade voters to accept the euro.

And, just as in 1992, a motley collection of impoverished popular movements and small parties from the fringes of the political spectrum is battling to keep the krone. Although the odds might seem stacked against them, the Euro-sceptics are in with a strong chance to upset the government's European agenda once more.

"It will be a close race. The chances are 50:50 so every vote counts," Drude Dahlerup, a professor in gender studies and a leader of the anti-euro June Movement, said. Ms Dahlerup's arguments against the single currency are clear. For the left-leaning June Movement and other Euro-sceptic groups, the single currency represents a big step on the slippery slope towards a United States of Europe.

Co-operation on a European and global level is desirable, she said, but this must involve free and independent nations, not elements of a pan-European superstate.

National sovereignty is a big theme in this campaign. Populist and nationalist parties on the far right have even suggested that a Yes to the euro would mean the end of the Danish monarchy. The pro-euro lobby, and the more sober elements of the left-wing anti-euro side, have rubbished this notion.

But arguments like this, which pander to people's fears about the viability of their way of life and culture, are finding a ready ear among large sections of the population.

Another chief argument on the No side is the future of Denmark's extensive and cherished welfare state. Despite cutbacks in recent years, the Danish welfare model still has the capacity to provide free healthcare, inexpensive childcare, free education and decent old-age pensions to all citizens. Eurosceptics say the single currency will jeopardise this welfare model.

This particular contention incenses the Prime Minister, Poul Nyrup Rasmussen, who called a special press conference to reject the implied threat. "European co-operation over the last 28 years has had no negative impact on old-age pensions and the euro will not alter this," he said.

His opponents, he said, were scaremongering and trying to cash in on angst. But scaremongering or not, Mr Nyrup Rasmussen and his fellow Europhiles in the other mainstream political parties are still having a tough time in winning over the electorate.

Although disenchantment with the political establishment has not reached the same levels as in Ireland, a great many Danes doubt the promises of their leaders. "None of them tells the truth," said Ingrid Thonbo, a catering manager in Malov, a sleepy commuter town outside Copenhagen.

Ms Thonbo was also immune to the pro-euro argument that economic chaos would be the upshot of a No. "I'm not nervous about the future. I don't believe the doomsday predictions," Ms Thonbo said.

And while Mr Nyrup Rasmussen has lashed out at his opponents, they have also accused the government of trying to frighten voters into a Yes.

During various stages of the campaign, the Prime Minister has said that a euro rejection would raise mortgage repayments; the Economy Minister has said that a tighter fiscal policy (austerity package) could be necessary and the Finance Minister has claimed that a No could cost Danes 5 billion kroner a year.

But despite the hectic campaigning and the mutual trading of insults there is very little real rancour. A civilised search for consensus and compromise is a cornerstone of the Danish political and social system.

Families may be divided on the issue of the euro but they will not be split.

The Haekkerup brothers agree to differ and also agree that each other's opinions deserve respect, even though Klaus, the younger of the pair, acknowledges that his refusal to toe the official party line will hardly help elevate him from the backbenches to cabinet.

Bengt Burg, the popular TV presenter of Denmark's version of The Wheel of Fortune, recently came out in public as a Euro-sceptic with a heartfelt appeal against the Brussels bastion.

"I'm not interested in the economic aspects but it is extremely important that we protect the environment and nature. I do not think that the European Union can guarantee a sustainable society," he told a meeting in a Copenhagen suburb.

Just a few hours earlier, on the other side of town, Mimi Jacobsen, an MP for the vehemently pro-euro Centre Democrats, took the podium in parliament and made an impassioned plea for a Yes to the single currency.

Mr Burg and Ms Jacobsen are married. Despite their differences on the euro, they intend to stay wed.

Clare MacCarthy is Denmark correspondent for the Financial Times.