No one has campaigned harder for Denmark to join the European single currency than the country's prime minister, Poul Nyrup Rasmussen.

But as his tireless campaign culminated in wooing women voters with roses, Danes voted 53 per cent against 47 per cent in a referendum on Thursday to keep the krone.

The 57 year-old Social Democrat leader described the result as a "defeat" which might isolate his country. But he said that Denmark will continue to play its full part in future development of the European Community.

He is also aware that more than the Danish krone is at stake. Other countries such as Norway, Sweden and the UK, who have held out against entering the European Monetary Union, could be influenced by the "no" vote. Both Sweden and the UK plan to hold referenda on the euro.

Mr Rasmussen's campaign, which started in March, has not been a bed of roses. In a bid to gain more "yes" voters, he had planned to ask the other 14 European governments to pledge they would not tamper with Denmark's generous welfare system if the country agreed to join the euro. But he was obliged to ditch the move when he realised it would likely create further doubt in the minds of eurosceptics.

He had been attempting to persuade the electorate that the euro would safeguard jobs and hold down mortgages. But voters have been more worried about the country becoming an insignificant part of a European superstate.

"Denmark is a small country and people are worried that it will lose its decision-making powers", says Peter Oppenheimer, a global strategist at HSBC.

Mr Rasmussen may also have started out wrong-footed on the campaign trail. At first he couched the debate in economic terms, while many Danes saw joining a single monetary system as a political issue and a matter of national identity.

Nor has Mr Rasmussen's crusade been helped by a euro that has remained weak on foreign exchange markets. On Friday, the euro lost some ground against the dollar but the possibility of furthe r central bank intervention in support of the currency helped limit losses.

The euro opened at $0.8808 in London on Friday, down from Thursday's close of $0.8829.

The "no" vote presents an unusual setback for Mr Rasmussen, who enjoyed a meteoric rise through the political ranks to become prime minister in 1993.

The son of working-class parents in the town of Esbjerg who worked to help his family make ends meet, Mr Rasmussen earned a master's degree in economics from Copenhagen University in 1971. He began work as an economist for the Danish Federation of Trade Unions, eventually becoming chief economist there. In 1987 he left to become vice chairman of the Social Democratic party.

Mr Rasmussen only won a seat in Parliament in 1988. But he managed to take over as head of Denmark's Social Democratic party four years later when he successfully challenged its then-leader, Svend Auken.

As it happens, Mr Rasmussen took up the prime minister's reins just a year after Denmark reject ed the Maastricht Treaty in a referendum, a move that shook the future of the European cooperation.

It was not until 1998 that Mr Rasmussen finally secured a "yes" vote for the treaty after negotiating a number of opt-outs from the monetary union and other key areas.

In his early days of office he seemed uncomfortable in the premier's hot seat but steadily grew in confidence.

Putting a brave face on defeat, Mr Rasmussen said the rejection of joining the single currency does not mean Denmark has turned its back on Europe.