Voters in Scotland are deciding whether to seek independence from the U.K. in a ballot that could spell the end of a three-century-old union that once dominated the world from America to Australia and trigger a new era of self-determination across Europe.

Polling stations opened at 7 a.m. local time in schools, church halls, libraries and community centers across Scotland for the country’s 4.3 million-strong electorate, and will close at 10 p.m.

The referendum is the culmination of almost two years of competing arguments over the viability of an independent Scotland, its economic well-being, currency and international standing. Polls suggest the final result announced in Edinburgh tomorrow morning will come down to those voters who were not persuaded by either campaign and must now make their choice.

“The emotional or intuitive side doesn’t get formed by showing a graph of where oil production will be in 2030,” said Harris Mylonas, assistant professor of political science at George Washington University and author of “The Politics of Nation-Building.” “Once you’ve reached the conclusion that the current situation is wrong, then you attribute value to other things that trump your economic interests.”

Alex Salmond, the head of the devolved Scottish government who leads the ‘yes’’ campaign, and U.K. Prime Minister David Cameron, who opposes independence along with the other main U.K. party leaders, used their final campaign speeches this week to stir passions that go beyond costings and statistics.

‘Seize It’

This is the “eve of the most exciting day in Scottish democracy,” Salmond told his campaign’s final rally last night in Perth, central Scotland. “This is our opportunity of a lifetime and we must seize it with both hands.”

Cameron used his final appearance in Scotland before the vote, in Aberdeen on Monday, to plead with Scots to stay with the union and not risk a “painful divorce.” Appealing to hearts as much as heads, Cameron’s Labour predecessor, Gordon Brown, yesterday evoked Lady Macbeth to warn against a vote for independence, saying that “once it’s done, it’s done.”

With a record 97 percent of the electorate registered to vote and turnout upward of 85 percent forecast, the result may not be known until until 6 a.m. or later tomorrow.

A final flurry of opinion polls on the eve of the vote showed the Better Together campaign retaining a slim lead. In the largest survey yet, YouGov Plc polled 3,237 people on Sept. 15-17 and found “no” support at 52 percent to 48 percent for “yes” when excluding undecided respondents. A poll by Survation for the Daily Record newspaper put the “no” lead at six percentage points, while a third poll, by Ipsos-Mori for STV, put the “no” campaign ahead by 51 percent to 49 percent.

Undecided Voters

All major polls show enough people are undecided to tip the result. Depending on the survey, there are between 170,000 and 990,000 voters yet to make up their mind based on the percentage of respondents and the number of registered voters.

The referendum has been particularly hard for pollsters to gauge because there is no real historical precedent to base findings upon, said Joe Twyman, head of political and social research at YouGov. He cited “silent no’s,” or people who are keeping it quiet that they’re preparing to vote against independence, as one group stoking uncertainty.

“How many of those we have, we simply don’t know,” Twyman said in an interview. “If I had to bet my house on it, I would say ‘no’ is going to win, but you never know.”

The results from the 32 council regions will start emerging in the small hours of tomorrow morning. There are a number of bellwethers for how the result may go.

Dundee, Ayrshire

Bookmakers Ladbrokes Plc has the city of Dundee, whose council is run by Salmond’s Scottish National Party, with the shortest odds, or most likely, for the largest “yes” vote. The longest odds are for places like the Scottish Borders and South Ayrshire, where the Conservatives have the most council seats.

Early declarations where each side will look for signs the result will go their way include East Lothian, home to the Open golf championships venue Muirfield, and North Lanarkshire, a traditional Labour heartland. The Yes Scotland and Better Together campaigns have both said they need to persuade Labour voters to back them if they are to win.

There are some wildcards: The electorate includes about 110,000 voters age 16-18 after the threshold was lowered for the referendum. The vote is also open to residents of Scotland rather than just U.K. citizens, meaning people from the European Union and Commonwealth are eligible to cast a ballot.

‘No Sympathy’

It won’t just be politicians in London and Edinburgh looking on. Groups with their own aspirations for independence across Europe are drawing on Scotland to push for similar votes, particularly in Catalonia.

Spanish Prime Minister Mariano Rajoy yesterday responded to a question from a Basque lawmaker in parliament by saying he had “no sympathy at all for these processes. They are bad for the state in question and for the whole of the European Union.”

U.S. Treasury Secretary Jacob J. Lew last night added his voice to the many outside figures who have expressed their preference for the U.K. to remain whole, saying that the Obama administration “has made clear a strong, united United Kingdom is important.” The White House later said via Twitter that Obama sees the U.K. as an “extraordinary partner for America and a force for good in an unstable world.”

Andy Murray

Tennis player Andy Murray, a Scot, backed the “yes” campaign overnight. “Huge day for Scotland today,” Murray said in a Twitter posting. “No campaign negativity last few days totally swayed my view on it.”

A conflation of events have put the vote on a knife edge, saying more about divergence within the U.K. than the desire of Scots for freedom or even to get rid of nuclear weapons and spend the money on the health service.

First, there’s the widening gap between politics in Scotland, where Salmond’s SNP has run the government since 2007, and England, where the anti-EU U.K. Independence Party is gaining ground. Secondly, there’s the weakening of the Labour Party, which lost to Cameron in 2010 only to be trounced by the SNP in Scotland a year later.

“It’s a perfect storm,” said Matt Qvortrup, senior researcher at Cranfield University and author of “Referendums and Ethnic Conflict.” “In one way, this happens all the time: countries become independent. Yet it also would be momentous, the disuniting of a union that’s lasted so long.”

It’s been almost two years since Cameron and Salmond signed the Edinburgh Agreement that set out the terms of the referendum. It was heralded by both sides as a gentlemen’s accord, with both promising to uphold the result.

The campaigns became increasingly heated and culminated this week in accusations of scaremongering and lies over inflated oil-revenue figures, price increases for Scottish consumers, the domicile of banks and who could best safeguard the health service. Police said they were on standby for any tension today, while the Church of Scotland appealed for unity as people cast their votes.

Canal Dreams

Salmond, in a letter to voters published yesterday, said people should dismiss the “increasingly desperate” scare stories over independence.

If the U.K. politicians opposed to Scottish independence are looking for a favorable omen before today’s referendum, Patrick Thompson’s house boat moored on the Union Canal in Edinburgh might suffice.

Posted in two of the barge’s windows for the benefit of passers-by are blue and green “yes” signs in support of the nationalists. The vessel’s name, “Narrow Escape,” captures what the outcome would be for Cameron if it’s a “no” vote.

Thompson, 59, who has lived on the boat for the past three years and put up his posters at the start of the campaign, says he’s voting to break Scotland from the U.K. so “it’s easier to get rid of politicians we don’t want.”

“I still believe that Scotland is a beautiful country obviously, but there’s a lot of talent in Scotland, it’s not just about oil,” he said in an interview this week.

Ann Clelland, 65, who works part-time as a supply teacher for special-needs children, said the lasting legacy of the campaign will be the political vitality injected into every level of Scottish society.

“What’s really amazing is how people on the street are all talking about politics,” she said in an interview in Perth, where she attended the final “yes” campaign rally. “I can’t imagine this energy dying if there is a ‘no’ vote.”

(Source: Bloomberg)