Austria on Wednesday adopted tougher asylum rules and announced plans to police its border with Italy, amid rising popular support for far-right policies.
The parliament voted for amendents that allow the government to take restrictive measures if it finds that the inflow of refugees overwhelms public institutions or poses a risk to public order.
The emergency measures would see nearly all asylum seekers rejected at the border.
Only unaccompanied minors, women with small children, asylum seekers with close relatives in Austria and those who face inhumane treatment if they are sent back would be allowed in.
The bill was adopted with votes from the government coalition's Social Democrats and centre-right conservatives, who have shed their welcoming stance towards migrants in past months as the right-wing Freedom Party (FPOe) has overtaken them in opinion polls.
The cabinet of Social Democratic Chancellor Werner Faymann has come under additional pressure since Sunday, when FPOe candidate Norbert Hofer won the first round of presidential elections with more than a third of the vote.
The FPOe voted against the amendment Wednesday because it had sought even tougher measures, while the Greens warned that the bill was unconstitutional.
"Asylum law is being annulled," Green leader Eva Glawischnig said.
Interior Minister Wolfgang Sobotka argued that those who already live in Austria had a right to live in security, not only those who seek refugee protection.
"Our capacity limit is geared towards Austrians," he said.
Earlier on Wednesday, police said it was making preparations for a 400-metre-long fence and strict controls at a key border crossing to Italy, as authorities expect the daily number of arriving refugees to rise considerably.
Regional police chief Helmut Tomac did not give a start date for the controls at the Brenner mountain pass, which have raised Italy's concerns over negative effects on freight business along this key North-South transportation route.
The daily Tiroler Tageszeitung reported earlier that police plan to introduce checks at the Brenner in late May or early June, in line with recent comments by Minister Sobotka.
The interior chief is set to travel to Rome on Thursday to discuss the controversial plans with the Italian government.
Currently, some 50 migrants arrive at the Brenner each day. That figure could rise to 500 in the coming weeks and months, the Tiroler Tageszeitung reported, citing police estimates.
Italian Prime Minister Matteo Renzi said the scheme was fundamentally misguided.
"The possibility of closing the Brenner is blatantly against European rules, as well as against history, against logic and against the future," Renzi wrote in an online newsletter.
"Free movement is the biggest achievement of the European Union and I am very determined to defend it and strengthen it, as is all of the [EU] Commission," EU Migration Commissioner Dimitri Avramopoulos warned in an interview with the La Repubblica newspaper.
Police chief Tomac said traffic would be slowed down, vehicles would be checked, and trains from Italy would be stopped and searched on the Austrian side.
"Rail traffic will be substantially delayed," Tomac said.
CGIA Mestre, an economic think-tank, said one third of goods that are imported or exported from Italy via truck pass through the Brenner. Together with rail traffic, more than 40 million tonnes per year are hauled over the mountain pass, according to the latest available data from 2013.
Police may also erect a mesh-wire fence on short notice to prevent migrants from disrupting traffic and to guide them to the manned checkpoint, Tomac told dpa.
A decision to raise the fence would depend on whether Italy cooperates on taking back migrants who are rejected by Austria, he explained.