As with the big independence decision itself, the issue of whether Scottish citizens living outside their homeland should be allowed to vote on the country's future is the source of fevered debate.

An estimated 1.15 million Scots will be watching from the sidelines on Thursday when the country decides whether or not to break away from the United Kingdom -- including many high-profile campaigners such as James Bond actor Sean Connery, a pro-independence champion.

While many accept the terms of the referendum agreed by London and Edinburgh which only allows current residents of Scotland to vote, others are furious that they will have no say on Scotland's future, with some declaring their exclusion illegal.

In March, London-based solicitor Aidan O'Neill sent Scottish First Minister Alex Salmond and British Prime Minister David Cameron legal opinion arguing that the terms violated Scottish expats' right to freedom of movement under European law.

The challenge was backed by former Scotland rugby player Kenny Logan and national football manager Alex McLeish.

But the Scottish government dismissed it, saying the agreement between London and Edinburgh "has put the referendum beyond effective legal challenge".

Some of the Scottish diaspora in the European Union -- which guarantees free movement of citizens -- are concerned that they may become illegal immigrants if the EU blocks moves for it to become a member in the event of a "Yes" victory.


Expats feel 'extremely aggravated'

With all legal avenues blocked, angry expats have taken to social media to voice their frustration.

"As a true born Scot and at present living outside Scotland I have been denied a vote on the future of HOME," wrote one poster on the Facebook page of campaign group "Extend Scottish Independence Referendum vote to all Scottish Citizens".

"It is only because you're scared that you won't get your way in the referendum, Alex (Salmond) and co," added another.

London School of Economics researcher Tony Travers also suggested that the terms of the referendum may have been decided on tactical grounds.

"Within Scotland, and certainly for Scottish nationalists, there will have been a fear that Scots living outside Scotland were less likely to vote for independence," he told AFP.

The researcher added that many expats "feel extremely aggravated" that foreign nationals currently residing in Scotland -- some for only a matter of weeks -- will have more of a say than them on Scotland's future.

He pointed out that many other Britons in the rest of the UK also felt "they are having something done to them over which they have no control".

But others accepted that living outside Scotland precluded them from voting.

"Obviously, I am a patriotic Scotsman and I would like to vote but I don't live there, I don't contribute and it is not going to affect me," Craig Stephen, a Glasgow native working in Hong Kong's finance sector, told AFP.


'Yes' camp 'more vocal'

Graham Wallace, a Scottish-born teacher at an international school in Italy, said: "I'm somewhat frustrated about not being able to vote.

"But there's such a diaspora of Scots around the world that it would be almost impossible to determine who does and doesn't have the right to vote."

In Paris, Colin Shepherd, landlord of the Pure Malt Scottish pub said: "I think it's very fair".

"I've lived away from Scotland for 12 or 13 years now and I think it's quite correct that people who currently live in Scotland are the people that have the vote."

Shepherd revealed he would support independence, but across the globe, expat opinion is divided.

Margaret Frost, chairwoman of The Scottish American Society, which brings together expats and Americans of Scottish descent, said it was "50-50" within the group.

"Those who are for it are more vocal," she explained. "The members that we have from the Highlands and the outer isles are more for it."

As examples of Scotland's deep influence on US history, Frost cited the Scottish heritage of various presidents, the presence of the of the Scottish saltire on the Confederate flag and the piece of Armstrong tartan carried by Neil Armstrong during his lunar mission.

She said the debate had remained good natured.

"If independence does go through, I suspect some will want to celebrate and we will probably celebrate with them," she explained.

"There doesn't tend to be the animosity there appears to be in Scotland."

But for many expats, passions still run high.

"Any Scotsperson who doesn't vote 'Yes', shame on them," said Wallace.

"If the votes turns out to be a 'No', I am no longer Scottish, I would be ashamed. "