Sweden is voting on whether to adopt the euro currency, just days after the murder of popular Foreign Minister Anna Lindh - a strong euro supporter. This is the first referendum on the euro since Denmark rejected the common currency in 2000, and analysts are closely watching the outcome. Opinion polls show that support for the euro has suddenly grown, after months of being in the negative column, but the outcome remains uncertain.

One poll shows those supporting the euro ahead by one percent, but another one shows those who oppose ahead by six percentage points.

Swedish Prime Minister Goran Persson, a Social Democrat, is leading the drive for Sweden to adopt the euro. He says a 'no' vote will leave the country without a voice when the European Union makes key economic decisions.

Supporters also say accepting the euro will help the economy of Sweden, a nation of nine million, by simplifying trade with the 12-nation zone that already uses the common euro currency. They argue that a small currency like the Swedish krona is more vulnerable to speculation and other pressures than the euro, which is the world's second largest currency after the dollar.

But opponents question what it will mean for Sweden's cradle-to-grave welfare state, which is supported by some of the world's highest taxes. Critics argue that the euro is risky and that being under the European Central Bank's monetary policy, which limits budget deficits and inflation, will hurt Sweden's economy.

The vote is being closely watched by Britain and Denmark, the other two EU nations that do not use the euro. Britain has not yet decided on whether to put the issue before voters. Denmark rejected the euro in a 2000 referendum.

All of this is in the shadow of the murder of popular Foreign Minister Anna Lindh, a strong campaigner for the euro. She was stabbed by an unknown attacker in a Stockholm department store Wednesday and died Thursday.

Police are circulating video pictures of a dark-haired man in a baseball cap and sweater. The killing stunned the nation. Election day in Sweden is usually a festive occasion, but the killing of Anna Lindh has placed a dark cloud over the event.