By Helen Popper
BUENOS AIRES (Reuters) - Voters in the remote British-ruled Falkland Islands hold a referendum on their future on Sunday that seeks to challenge Argentina's increasingly vocal sovereignty claim.
Thirty-one years since Britain and Argentina went to war over the windswept archipelago in the South Atlantic, tensions between London and Buenos Aires are running high. That has unsettled some of the roughly 2,500 islanders and strengthened patriotic feeling.
Just 1,649 Falklands-born and long-term residents are registered to vote in the two-day referendum starting on Sunday in which they will be asked whether they want to remain a British overseas territory.
A near-unanimous "yes" vote is likely, prompting Argentina to dismiss the referendum as a publicity stunt. British bookmaker Ladbrokes described the result as "the biggest certainty in political betting history" and said no one had placed a bet on a "no" vote.
But high turnout is expected as islanders embrace the ballot as an opportunity to make their voices heard.
"People feel strongly about this. It's our chance to make a unified stand on something that affects us deeply," said Kerri Jamieson, a Falklands-born small business owner who has been selling commemorative referendum T-shirts.
So far she has sold about 50 T-shirts bearing the logo "Our Islands, Our Decision," and the orders keep coming in.
Jamieson lives in a remote West Falkland settlement, where a mobile voting station will be flown in to allow the handful of residents to cast their ballots.
In the quiet island capital of Stanley, where most islanders live, the post office has produced a line of official stamps to mark the occasion.
"For the Argentines, it's just an academic exercise, but for us, it affects us enormously," Jamieson said.
Islanders say fiery remarks by Argentine President Cristina Fernandez and her foreign minister, Hector Timerman, have fueled patriotic sentiment on the islands, which lie nearly 8,000 miles from London and just a 75-minute flight away from southern Argentina.
Tensions have risen with the discovery of commercially viable oil resources in the Falklands basin and Fernandez's persistent demands for Britain to hold sovereignty talks over the Malvinas, as the islands are called in Spanish.
Timerman said last month the referendum had the "spirit of a public relations campaign" and government allies have questioned its legitimacy.
"It's almost an act of self-satisfaction to ask British people if they want to be British. As far as we're concerned, it seems completely meaningless," said Senator Daniel Filmus, head of the Senate's foreign policy committee.
Argentina has claimed the territory since 1833, saying it inherited it from the Spanish on independence and that Britain expelled an Argentine population from the islands.
The sovereignty claim is a constant in Argentine foreign policy, but there have been moments of detente since former dictator Leopoldo Galtieri sent troops to land in the Falklands in April 1982, drawing a swift response from former British Prime Minister Margaret Thatcher.
The 10-week war, which killed about 650 Argentine and 255 British troops and ended when Argentina surrendered, is widely remembered in Argentina as a humiliating mistake by the discredited dictatorship ruling at the time, and no one advocates military action.
"There is absolutely no chance - not today, tomorrow or ever- that Argentina will look for a solution beyond diplomacy and peace," Filmus said.
Still, more than three decades since the war, the islands remain a potent national symbol in the South American country.
Everything from soccer stadiums to pizza parlors are named after the Malvinas and their craggy outline is a familiar site in street graffiti and badges worn proudly by war veterans, many of whom support the government's tough line on sovereignty.
"This colonial situation is unsustainable in the 21st century," said Mario Volpe from the CECIM veterans center in the central city of La Plata.
Plans by London-listed firms to tap offshore oil and gas deposits near the Falklands, which could make the prosperous islands even wealthier, are branded as looting in Argentina. That has not deterred the companies and the islands are set to start producing their first oil in 2017.
While the sovereignty claim unites political rivals in Argentina, there is growing criticism of Fernandez's approach.
"Today we're in a worse position than ever... we've never been so far from (sovereignty talks)," said Andres Cisneros, who was deputy foreign minister during a relative thaw in relations with the islanders in the 1990s.
He said the referendum "will give the government further justification for deepening a policy of hostility that mainly benefits the British."
Cisneros said the sovereignty dispute is a bilateral issue that must be resolved between London and Buenos Aires.
That argument is rejected by islanders, some of whom are the descendants of British settlers who arrived eight or nine generations ago.
"We feel that gives us some kind of separate identity," said John Fowler, deputy editor of the islands' weekly newspaper, the Penguin News.
"We're no more implanted or imposed than the majority of the people of Argentina ... Like them, we're an immigrant society."
Most islanders say they do not expect Fernandez to take heed of the referendum's result, which is to be announced at about 2300 GMT on Monday.
Their biggest hope is to garner global support.
"This isn't really about Argentina, this isn't really about the United Kingdom, this is about us - the Falkland islanders, our country," said Gavin Short, one of the Falklands assembly's eight elected members.
"We're the people who really matter in all this."
(Additional reporting by Juan Bustamante in Buenos Aires and Guy Faulconbridge in London; Editing by Kieran Murray and Vicki Allen)