Three EU member states violated the law by refusing to comply with the bloc's migrant sharing scheme, the Advocate General said. The opinion is not legally binding, but is often adopted by Europe's top court.
Hungary, Poland and the Czech Republic broke EU law by refusing to accept asylum seekers under the bloc's mandatory migrant quota scheme, an advisory body to the European Court of Justice said on Thursday.
In December 2017, the European Commission took the three EU member states to Europe's top court after they refused to take in refugees who arrived in Greece and Italy at the height of the 2015 migrant crisis.
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The former communist states had argued that accepting asylum seekers would threaten security and cultural cohesion — and that Brussels had no legal grounds to implement mandatory migration quotas.
In an opinion advising the European Court of Justice, Advocate General Eleanor Sharpston said Hungary, Poland, and the Czech Republic had no legitimate security grounds to reject the quota scheme.
The respect for rule of law requires member states to comply with legal obligations, said Sharpston, whose opinion is not legally binding but is usually followed by the European Court of Justice.
"Disregarding those obligations because, in a particular instance, they are unwelcome or unpopular is a dangerous first step towards the breakdown of the orderly and structured society governed by the rule of law," the advocate general said.
"The principle of solidarity necessarily sometimes implies accepting burden-sharing," she added.
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Europe's top court is expected to rule on the case next year. It can fine member states that violate EU law.
The 2015 quota scheme was meant to relieve migrant pressure on Greece and Italy by dividing 160,000 asylum seekers among the bloc's 28 member states. Hungary, Poland, and the Czech Republic took in only a handful of the 10,000 asylum seekers they were expected to take under the burden-sharing agreement.
The European Commission dropped the scheme in September 2017 after only some 30,000 migrants had been distributed.
The case was at the center of an ongoing dispute within the bloc over how to handle the arrival in southern countries on the Mediterranean of more than a million migrants, most fleeing war in the Middle East or poverty and conflict in Africa.
While the 2015-16 crisis is over, the issue of European solidarity continues to divide the bloc at a time Germany is warning of a repeat of the migrant crisis due to the conflict in Syria and instability in Africa.
cw/rc (AP, dpa, Reuters)