France's nickel-rich Pacific territory of New Caledonia voted on Sunday in a third and final referendum on independence -- with some of those wanting to break free demanding a boycott because they say the Covid pandemic is preventing a fair ballot.

Turnout was sharply down on the two previous polls, with just 27.8 percent voting by midday (0100 GMT), compared with 49.4 percent at that stage in the 2020 vote, according to the islands' high commission.

At the Candide-Koch polling station in the capital Noumea, a short line of voters queued in the oppressive heat.

New Caledonia gets to vote one last time on independence from France
New Caledonia gets to vote one last time on independence from France AFP / Theo Rouby

"This referendum does not make too much sense because half the population has decided not to vote," said Cathy, a bookseller, who gave only her first name.

"I came out of civic-mindedness, what interests me is the society we are going to build afterwards," she told AFP.

The territory of about 185,000 voters, 2,000 kilometres (1,250 miles) east of Australia, was granted three independence referendums under a 1988 deal aimed at easing tensions on the islands.

Pro-independence campaigners want to postpone the vote because of a spike in Covid cases
Pro-independence campaigners want to postpone the vote because of a spike in Covid cases AFP / Theo Rouby

Having rejected a breakaway from France in 2018 and then again last year, the inhabitants are being asked one last time: "Do you want New Caledonia to accede to full sovereignty and become independent?"

At stake is one of France's biggest overseas territories, with about 10 percent of the world's nickel -- used to make stainless steel, batteries and mobile phones -- and a key strategic asset in the contest between the West and China for power in the Indo-Pacific.

"If the French safeguard disappears, all elements would be in place for China to establish itself permanently in New Caledonia," said international relations analyst Bastien Vandendyck.

France regards itself as a major Indo-Pacific power thanks to overseas territories like New Caledonia
France regards itself as a major Indo-Pacific power thanks to overseas territories like New Caledonia AFP / Theo Rouby

Other nations in the region, including Fiji, Vanuatu, the Solomon Islands and Papua New Guinea, had already become "Chinese satellites", Vandendyck told AFP.

"All China needs now to complete its pearl necklace on Australia's doorstep is New Caledonia," he said.

Map and key dates in the history of New Caledonia.
Map and key dates in the history of New Caledonia. AFP / Laurence SAUBADU

Pro-independence campaigners are boycotting the vote, saying they want it postponed to September because "a fair campaign" is not possible with high coronavirus infection numbers.

"I don't want to go and vote because I don't agree with this final poll," said Noumea resident Jean-Pierre Wadra.

New Caledonia's 270,000 inhabitants were largely spared during the pandemic's first phase, but have suffered close to 300 Covid-19 deaths since the Delta variant appeared.

Turnout appeared to be sharply down on the two previous referendums
Turnout appeared to be sharply down on the two previous referendums AFP / Theo Rouby

The pro-independence movement has still threatened non-recognition of the referendum outcome and vowed to appeal to the United Nations to get it cancelled.

Authorities deployed 2,000 police and troops for the vote, which had passed off without incident so far, according to the high commission, although police intervened over an attempted roadblock on an outlying island.

Whichever way the poll goes, the controversy is likely to rumble on: "It's going to be a mess in New Caledonia," Wadra said.

The French minister in charge of overseas territories, Sebastien Lecornu, said the boycott would make no difference to the referendum's "legal validity".

The vote comes against the backdrop of increasingly strained ties between Paris and its regional allies.

France regards itself as a major Indo-Pacific player thanks to overseas territories such as New Caledonia.

President Emmanuel Macron has insisted the French state takes no side in the referendum, other than to ensure fair and smooth proceedings.

Behind a recent French-Australian spat -- over submarine contracts -- looms China's growing role in the region, with experts suspecting that an independent New Caledonia could be more amenable to Beijing's advances.

China is already the biggest single client for New Caledonia's metal exports.

The pro-French camp, meanwhile, has called on supporters to turn out, fearing the boycott by pro-independence parties may prompt them to stay at home with victory looking like a foregone conclusion.

In June, various political parties agreed with the French government that the referendum, whatever its outcome, should lead to "a period of stability and convergence" and be followed by a new referendum by June 2023 which would decide on the "project" New Caledonia's people want to pursue.

But hopes for a smooth transition were jolted when the main indigenous pro-independence movement, the FLNKS, deemed the government's insistence on going ahead with the referendum "a declaration of war".

Observers fear renewed tensions could even spark a return of the kind of violence last seen 30 years ago.

Polls close at 6:00 pm (0500 GMT) with the results expected a few hours later.