The low-key but simmering tussle between Britain and Argentina over the Falkland Islands has taken a new symbolic turn.

Countries belonging to the Mercosur trading bloc, at a meeting in Montevideo, Uruguay, indicated they viewed the British Overseas Territory off their coast a colonial hang over and agreed to bar ships flying the Falklands flag from their ports.

"This territory is a colonial British position in our America," said Uruguayan President Jose Mujica.

" … All measures that can be put in place to impede the entry to its ports of ships that fly the illegal flag of the Malvinas Islands (the Falklands)" would be adopted by Mercosur countries, the organization said in a statement.

The statement and closing of ports angered Whitehall, which is seeking clarification from Mercosur countries but so far the action appears more symbolic than practical.

In addition to Argentina, only three other countries belong to Mercosur -- Brazil, Uruguay and Paraguay -- and Paraguay is landlocked. And Falkland Islands boats bringing goods to market or transporting cargo to the archipelago are legally entitled to fly the Union Jack.

"We want to work with Argentina … but the Argentine government has continued to make statements which challenge your right to self-determination," British Prime Minister David Cameron said in a Christmas message to the islands after the Mercosur vote. "We will never negotiate on the sovereignty of the Falkland Islands unless you, the Falkland Islanders, so wish. No democracy could ever do otherwise."

The assurance was a reiteration of Britain's line in the sand over the territory, which has more sheep than people but also a potential bounty of oil and natural gas -- as much as 60 billion barrels of oil, 1998 geological surveys indicate. No wonder Buenos Aires, which contends it assumed sovereignty of the South Atlantic islands when it gained independence from Spain in 1816, refuses to let the matter of sovereignty drop.

"They're currently taking our oil reserves and fish stocks but when they need more natural resources they will come and use force to steal them whenever and however they can," Argentina President Cristina Fernandez de Kirchner warned at the Mercosur meeting.

The Falklands, called the Malvinas by Argentina, is located off the coast of the South American mainland. It has two main islands. Residents number only about 3,000; sheep number more than 500,000. Britain and Argentina base their claims on 18th-century settlements on the islands.

In 1982 Argentina's military junta occupied the islands, whose people are British, sparking a 74-day war in which Britain sent a naval task force and retook the islands. More than 600 Argentineans and 200 British troops were killed.

In a new re-assertion that the Falklands/Malvinas belong to Argentina, Buenos Aires recently ruled that ships fishing in the waters around the islands must first seek permission from Argentina, and its navy has begun boarding vessels to enforce its stricture. And it has continued lobbying in the United Nations over the issue.

The sabers of both countries remain in their scabbards but that hasn't stopped comments by officials and media that stir nationalist sentiment. In both countries, media have begun printing stories about the military of their adversary planning to flex muscles.

Argentina has would seem to likely have an upper hand if push comes to shove. First there is the question of distance from Britain. And then there is the issue of Britain's drawdown of naval assets amid budget cutting, which would make assembling a strong task force if necessary difficult indeed.

In the Falklands area are 1,200 British military personnel on the island, four jets and a frigate.

Argentina, meanwhile, has 73,000 troops, 87 jet fighters, five destroyers, six frigates and three submarines, all within striking distance of the Falklands.

Despite Argentina's action on vessel flagging and boarding to vessels, both sides are currently limiting their duel to the verbal arena.