The previous day Lombardy's president Roberto Maroni not only ruled out taking in more migrants but threatened to cut regional funding to cities who took them in, prompting other northern regions to jump on the anti-immigration bandwagon.
Interior Minister Angelino Alfano slammed their behaviour as "profoundly unjust" as it risked placing ever greater strain on the poorer south, which despite struggling with high unemployment "has helped the state face this emergency."
Prime Minister Matteo Renzi expressed his frustration, saying it was "difficult to speak of immigration and ask for the European Union to be involved when some regions in your own country say the problem has nothing to do with them."
"What we need to do at the moment is solve problems, not by shouting but through action," he said, calling on the EU to take more people in because a May plan to relocate 24,000 refugees from Italy to other European countries "is not enough".
Answering reporters' questions after a G7 meeting in Germany, Renzi later stressed that places which took in migrants would be financially compensated.
'Even more alone'
A frantic weekend of rescues saw nearly 6,000 people plucked to safety from packed fishing boats and rubber dinghies off Libya, bringing the year's total of new arrivals on Italian soil to more than 50,000.
The prediction that many more are set to leave for Italy - and revelations in Rome of a criminal network exploiting newly arrived immigrants for financial gain - have sparked a backlash in right-wing quarters against the government.
But Renzi said Maroni, a former interior minister, was partly to blame for signing Italy up to the EU's Dublin treaty, which obliges asylum seekers to apply for refuge in their country of entry.
Lombardy, Italy's richest region, has taken in 9.0 percent of the country's approximately 76,000 asylum seekers, while Veneto has taken 4.0 percent and Liguria 2.0 percent. Sicily in the south has taken 22 percent, according to official figures.
The three northern regions have warned that they will not accept any more migrants.
EU migration commissioner Dimitris Avramopoulos, speaking at the same Rome press conference as Alfano, reiterated the European Union's "support" and "solidarity" with Italy on the issue, adding that it was not the only country dealing with the growing influx of migrants from the Middle East and Africa.
With Greece also under increasing strain from migrant arrivals, the issue is due to be back on the table at an EU interior ministers' meeting on June 16th.
But critics warned the bad press garnered by the northern regions' stance, following on the back of revelations of a one-eyed mobster's infiltration of the immigration sector, "risk Italy finding itself even more alone."