Swedes are voting on whether to join the 12-member euro zone today with the result wide open after sympathy for murdered pro-euro Foreign Minister Anna Lindh eroded a long "No" lead in opinion polls.
Polling stations opened at 8 a.m. (7 a.m. Irish time) and will close at 8 p.m. with preliminary results expected about 9:30 p.m.
An upset "Yes" vote in the broadly EU-sceptic Nordic nation would make it the first European Union state to endorse the 12-nation euro at the ballot box since its launch in 1999. A "No" would keep it outside with Britain and Denmark.
The Danes rejected the euro in a September 2000 referendum, which the "No" side won by 53-47 per cent.
Sweden had looked likely to return a resounding "No" until Ms Lindh, the popular 46-year-old foreign minister and mother of two, was knifed to death while shopping at a Stockholm department store.
Police hunting her killer circulated security video pictures of a dark-haired man in a baseball cap and grey college sweater. The man remained at large today, evoking painful memories of the 1986 assassination of Prime Minister Olof Palme a few blocks away by gunshot. Mr Palme's killer has not been found.
Some opinion polls showed a surge in support for the "Yes" side, which has lagged the "No" side since April.
Yesterday, a Gallup poll gave the "Yes" side, led by Prime Minister Goran Persson and supported by the political establishment and big business, a 43-42 per cent lead. But a Temo poll saw the "No" camp, with the support of the left, Greens and many women, winning by 46-40 per cent.
Eurosceptics say handing over monetary tools to the European Central Bank would leave them unshielded from economic shocks, while pro-euro Swedes think joining the final phase of Economic and Monetary Union would boost trade and ensure future growth.
Some seven million people are eligible to vote. Turnout in Swedish referendums is traditionally around 80 per cent.
All parties have vowed to respect the vote's result, which in the case of a "Yes" result would mean Sweden switching to euros for all transactions in 2006 at the earliest.