AUCKLAND -- Due east of Australia, and far removed from Europe, the Pacific island territory of New Caledonia is mulling a final break from France, ending a relationship lasting more than 150 years. In a referendum that will take place next year, New Caledonia will vote on the issue of independence.

The question that will be asked has not been determined, and neither has the eligible electorate. But tensions have worsened ahead of the vote, prompting former French Prime Minister Manuel Valls to promise in November that more soldiers would be sent to the territory to deal with the violence.

On Jan. 30, police were fired at in the region around the capital, Noumea, the latest in a spate of such attacks since an unarmed prison escapee was shot dead by police in October.

New Caledonia, a self-governing island with a population 260,000, has been ruled by France since 1853, but communal relations have been repeatedly scarred by failed revolts and violence between the indigenous inhabitants, known as Kanaks, and French settlers.

A 1987 referendum asked whether the territory should remain part of France, but was boycotted by the pro-independence group Front de Liberation Nationale Kanak et Socialiste, after Paris refused to allow United Nations supervision of the vote. Only 1.7% voted for independence.

Tensions continued to rise, and a year later FLNKS activists killed four French police and took hostage 27 others, together with a prosecutor and seven soldiers. A government-ordered assault finally freed the hostages, but 19 FLNKS activists and two soldiers were killed.

Valls acknowledged the increasing tensions in November, promising better security on the island, and noting that: "Even if we do everything we can to avoid it, we anticipate that the future will involve ... hazards and risks." He added, "The situation in New Caledonia has deteriorated in the area of security."

The French prime minister resigned shortly afterward, as part of an unsuccessful campaign to win the French Socialist Party's nomination for president in elections due in April and May. In a sign that New Caledonia could figure in the two-stage election, conservative Republican Party candidate Francois Fillon has already said he favors continued French sovereignty.

Meanwhile, there is no agreement on the electorate for an independence vote. Kanaks, who have lived on New Caledonia for 3,500 years, make up 39% of the population, according to a 2014 census. Europeans comprise 27%, and "Caledonians," who are mostly ethnic Europeans, account for 9%. The remainder are from other French Pacific territories such as Tahiti and Wallis and Futuna, together with some Indonesians, Vietnamese, Chinese and others.

Union Caledonienne, the main backer of independence, contends that voter registration procedures disenfranchise many Kanaks, while allowing shorter-term migrant voters onto the electoral roll. Its demand for systematic and unconditional registration of all Kanaks has been rejected by France, but Valls said before his resignation that the registration issue would be resolved by a census and a voter education campaign.

Anti-independence activists, some of whom have accused Paris of trying to push the territory into independence, say that people should not be registered to vote against their wishes.

What's the question?

There is also disagreement about the question that voters should be asked to answer. Pierre Frogier, leader of the anti-independence Rassemblement movement, said he was opposed to a simple question on independence, arguing that it would "result in the fragmentation of New Caledonian society and the incitement of Caledonians to fight."

Frogier, a former president of the island's government who now sits in the French Senate, said a referendum on independence risked destroying 30 years of working together on the island.

Opponents of independence have mobilized thousands of demonstrators in rallies against the independence vote, and control 29 of 54 democratically elected seats in the territory's law-making assembly. The remaining 25 members are split between those who favor independence and a group advocating a looser relationship with France.

Paul Soyez, a researcher in French-Australian relations at the Sorbonne University in Paris and at the University of Melbourne, said the wording of the referendum question was a serious problem for the French authorities, while there was a "quite high" risk of violence.

"The whole issue is to know how to phrase a question that will not be black and white but that will enable voters to choose between several forms of autonomy," he said.

Soyez said the prospect of violent clashes was "a real concern here in Australia, since stakeholders in Canberra don't know who Australian public opinion would support, France or Kanaks, and then who they would have to defend."

David Chappell, a University of Hawaii professor who has studied the island, said there was little direct dialogue between French loyalists and independence supporters, and noted that divisions were emerging within both groups.

Chappell, author of "The Kanak Awakening," said the loyalists would win an independence referendum, but forecast that the territory would shift closer to sovereignty over the next generation. "In a sense, the process of nation building is not suffering fragmentation of the old ethno-political blocs ... as much as it is diversifying within a still vague concept of nationhood," he said.

New Caledonia is one of several Pacific states and territories where people are agitating for new political leadership, including some in areas of countries that have already become independent.

Papua New Guinea, administered by Australia until independence in 1975, agreed on Jan. 24 to allow a referendum on independence in June 2019 in Bougainville, an autonomous region where constitutional tensions led to extensive violence in the 1980s and 1990s. Bougainville's future could also feature as a key issue in a Papua New Guinea general election in May.

Guam, a U.S. territory 2,500km south of Tokyo that hosts one of the largest American military bases in the Pacific, is also ironing out legal and constitutional issues ahead of a vote on its status. The territory has 165,000 residents, but only the 37% who are indigenous Chamorro have been offered a vote in a non-binding independence referendum.

A court challenge to the voting rules has delayed the announcement of a date for the referendum. Votes in 1982 and 1987 saw around 70% in favor of self-government, but no action was taken, leaving the island in political limbo.

"It's time that we confronted the fact that for nearly 400 years the state of our island has been colonial," Republican Governor Eddie Calvo said in February 2016, as the latest voting process started. "It is the unchanged and unrepentant shadow cast upon our long and unshackled destiny."

There is also talk of local independence within the Federated States of Micronesia, a sovereign nation of small islands that lies north of Papua New Guinea and east of the southern Philippines. The small state of Chuuk considered a break-away referendum in 2016 before backing away from the idea. But local elections on March 7 could revive the campaign.