A diplomatic row threatens to disrupt Italy's Alpine province of South Tyrol over the question of national identity and whether some of its inhabitants should have the right to Austrian citizenship.

Italy's wealthiest province elects its new autonomous parliament on Sunday as Vienna and Rome lock horns over a proposal by Austrian Chancellor Sebastian Kurz to offer Austrian passports to South Tyroleans. But the offer extends to speakers of German or the regional language Ladin, not to those who only speak Italian.While the passport issue isn't on the ballot per se, and other issues such as immigration have dominated the campaign, the dual-nationality question has nevertheless been a hot-button topic.

Proponents of dual citizenship claim it will forge a stronger European identity in the face of growing far-right and populist forces. But critics fear offering Austrian nationality only to German- and Ladin-speakers could prove divisive in a territory often held up as a model of peaceful cohabitation between the different linguistic groups. And a furious Italian government sees Kurz's proposal as an attack on its sovereignty.

"You can't give away passports without our consent," Interior Minister Matteo Salvini said at the weekend. "A dual passport is out of the question."

Vienna, which has yet to draw up a concrete road map for its scheme, has recently sought to calm the waters, promising to proceed solely with Rome's consent.

In South Tyrol's capital Bolzano, the low-key campaign is in evidence only through a few political posters in the town's green spaces. For retired bank employee Rene, Austrian citizenship would be a dream come true. "We have nothing to do with Italy. It'll give us back a feeling of belonging to our Austrian homeland," he told Agence France-Presse (AFP).

Part of the Austro-Hungarian Empire for over five centuries, South Tyrol was ceded to Italy after World War I, but awarded autonomous status. Subjected to forced "Italianization" by Benito Mussolini from the 1920s, just before World War II the province's German speakers were offered the option of "returning" to Nazi Germany or remaining as fully fledged Italians. In 1948, the rights of the three main language groups, German, Italian and Ladin, were enshrined in the territory's autonomy statute. But for many the dream of rejoining Austria, or attaining independence from Italy, never faded. There was even a series of separatist bombings during the 1950s and 1960s.

Everyone is required to identify with a linguistic group, and according to the latest figures from 2014, 65 percent of the half-a-million-strong population feel themselves to be German speakers, 27 percent Italian and four percent Ladin. All public signs are trilingual and most people switch effortlessly between Italian and German.