Migrant holding centres: first Germany, now Austria

"Should this agreement become the German government position, we consider it necessary to take action to fend off any disadvantages for Austria and its people," Austrian chancellor Sebastian Kurz and far-right deputy leader Heinz-Christian Strache said.

"If Berlin introduced national measures, which would have a chain reaction, it could mean that Austria would have to react," Kurz added in solo remarks to press.

Their words augured a clamp-down on the Brenner Pass through the Alps to Italy, prompting immediate howls of complaint from Rome.

"We [the EU] should enter a phase of cooperation," Italian foreign minister Enrico Moavero Milanesi said.

"The Austrian decision to close the Brenner would be against this spirit and so whoever put into practice would have to assume responsibility for it," he said.

The "chain reaction" comes after German chancellor Angela Merkel agreed with her interior minister, Horst Seehofer, to police the 90 crossing points along Germany's 500-mile southern border with Austria.

Migrants would be held in new detention centres, with those found to have first-entered the EU in, for instance, Italy, turned back "on the basis of an agreement with the Republic of Austria".

The deal still needs the blessing of the centre-left SPD party in Merkel's coalition to go ahead.

It has voiced horror over such centres in the past and said on Tuesday it still had "unanswered questions".

But the European Commission gave Merkel's plan a quick thumbs up, with its chief, Jean-Claude Juncker, saying in Strasbourg on Tuesday: "I have not studied it in detail, but at first glance, and I have asked the legal services to look at it, it seems to me to be in line with [EU] law."

The German debate also seemed likely to come down to rhetoric rather than substance, amid doublespeak on how the camps should be described.

"Transit centres are not prisons," German transport minister Stephan Mayer told Bild, a tabloid daily.

"In the centres everyone can move freely, but no one is allowed out," he said.

The Merkel-Seehofer deal comes after her interior minister, from the CSU, a minor party in the coalition, had threatened a rebellion that could have destabilised the government.

Germany recorded just 18,349 people this year who would be eligible for deportation to other EU states under the proposed scheme.

The number is drastically lower than at the height of the migration crisis, when hundreds of thousands of people entered Germany via Austria and Greece.

But it comes in a harsh new climate, with the CSU party trying to win votes from the far-right AfD party in elections in Bavaria, south Germany, in October, and with anti-immigrant populists already in power in Austria, Hungary, Italy, Poland, and Slovenia.

If the German deal goes ahead and Austria follows suit that is likely to prompt an even harder line in Italy, which already began refusing to take in migrant boats.

Its deputy PM Luig Di Maio said on Monday he would supply motor boats to the Libyan coastguard so that they could take people back to detention centres in Libya instead.

That would be "against our values, international law and European law … we are well aware of the inhumane situation for many migrants in Libya," an EU commission spokesowman said.

Europe's political crisis on migration, which began in Bavaria, was already sending ripples as far south as Africa, the International Organization for Migration (IOM), an international body, warned.

More than 1,000 people have drowned trying to reach the EU by sea in the first six months of the year, with a sharp increase in deaths and risky crossings in recent days and weeks, it said.

"Smugglers are exploiting the desperation of migrants to leave before there are further crackdowns on Mediterranean crossings by Europe," Othman Belbeisi, the IOM's Libya chief said.