The heads of the two parties supporting Italy's new government are clashing over a plan to conduct a census on the country's largely un-measured Roma population with an eye towards deporting those whose documentation is not in order.

At least 150,000 members of the nomadic Roma are thought to live in Italy, mostly near large cities like Rome, Milan, and Naples. As many as half are thought to be born outside of Italy or to be Italian-born non-citizens.

Matteo Salvini, Italy's minister of the interior and head of the nationalist League, one of the two parties supporting the government of Prime Minister Giuseppe Conte, started the row this week. Salvini said he instructed government officials to "prepare a dossier on the Roma question" in order to know "who they are, where they live, and how many of them there are."

Salvini said those without Italian citizenship would be deported, and he complained that for those with Italian citizenship, "Unfortunately, well, you have to keep them."

Salvini has not been shy about extreme views since the new government was installed on June 1. He has repeated his campaign promise to deport as many as half a million migrants from Italy, and earlier this month earned worldwide headlines after refusing to allow a rescue ship with 629 refugees on board to land in Italy.

"I will not quit," Salvini said on social media Tuesday. "We're moving forward," Salvini said, defending the counting of the Roma community in the country was necessary for reasons of security.

But the latest comments from the League have sparked the first rift with the Five-Star Movement, the other party backing the Conte government. Luigi Di Maio, minister of labor and head of the Five-Star Movement, said Salvini's order was "unconstitutional." Some lawmakers from the party said they would instruct officials to refuse to act on it.

Paolo Gentiloni, who was prime minister for 18 months until Conte was installed, also criticized Salvini's actions. "Yesterday the refugees, today the Roma," Gentiloni said via social media. "How tiring it is to be wicked."

Roberto Malini, from the activist organization Every One Group, told Xinhua that in attacking migrants and the country's well-established Roma population, Salvini was a way to divide the country.

"Salvini has been saying this kind of thing for years," Malini said. "His message has never been that everyone is the same, that everyone has the same rights. He is telling voters that everyone's rights are different, that some people are better than others."

The Roma population has deep roots in Italy, with some sources estimating they first arrived in the 14th Century. But they often live on the periphery of cities and rarely integrate into Italian culture. Polls show that at least three in four Italians say they have an unfavorable view of the Roma.

Former prime minister and billionaire media tycoon Silvio Berlusconi, a one-time ally of Salvini and the League, proposed a census of the Roma in Italy. But the plans were scuttled after an Italian judge ruled they were illegal.