At an extraordinary meeting in Brussels yesterday (12 May), ministers discussed the conditions under which countries should be allowed to reintroduce border controls for people travelling within the Schengen area.
The issue came to the fore after the arrival in Italy and Malta of thousands of people risking their lives to flee violence in Northern Africa.
Their arrival triggered a serious split between France and Italy after Rome issued temporary travel visas to thousands of Tunisian migrants, many of whom were heading to France. Paris responded by threatening to reintroduce checks along its south-eastern border.
Ministers from a large majority of EU member states have now endorsed the idea that the rules of the Schengen agreement need to be clarified in order to respond to such crisis situations.
They also agreed that these should only happen under exceptional circumstances and strict conditions in order to avoid "unilateral decisions".
Under what conditions and exactly how such decisions will be reviewed at European level is still being debated.
A definitive agreement is expected at the next EU summit in Brussels on 24 June.
"We don't want less Europe, we want more Europe," said French Interior Minister Claude Guéant after the meeting, seeking to address what he described as "misunderstandings" about France's intentions in the border dispute with Italy.
Asked about Denmark's unilateral decision on Wednesday to reinstate customs checks with Sweden and Germany, Guéant said: "It's not normal that, for managing a common area, individual decisions are setting the rules. It's just not possible."
"There must be rules that are set in advance to define the criteria that can characterise a crisis."
Hungary's Interior Minister Sándor Pintér, who chaired the meeting, said there was a consensus on the need to preserve the Schengen agreement.
"The free movement of persons throughout the territory is one of the key achievements of the Union and we have to maintain and safeguard this achievement," he said.
The Hungarian minister warned against the threat of a "chain reaction" if individual countries decided to reinstate border controls without a commonly agreed procedure.
Under the current rules, member states may reinstate border controls on a temporary basis when there is a threat to national security or public order, for example to prevent violent fans from attending international football games.
The EU's commissioner for home affairs, Cecilia Malmström, insisted that there was a need to make improvements without undermining the Schengen agreement.
"We do need to have increased clarity in the rules [and] procedures, in order to avoid unilateral uncoordinated decisions by member states," she declared.
She said the European Commission would elaborate clearer guidelines on how member states should interpret the rules of the Schengen agreement. "Only as a very last resort, under very clearly defined conditions, can there be a possibility to temporarily reinstate border controls," she insisted.
Commission's role still to be defined
However, the role of the European Commission in approving such decisions is still unclear.
The Commission believes that it should play a leading role in deciding when border controls could be reintroduced. However, many EU governments are not happy with the idea that Brussels should be allowed to decide how they can police their national frontiers.
"The Commission would like to play a role in this area," said Guéant, adding that some member states "are denying such a role to the Commission – at least exclusively".
Guéant suggested that this role could be endorsed by the Home Affairs Council, which represents the interior ministries of the 27 EU member states.
Denmark moves to counter media reports
Arriving in Brussels for the meeting, Danish Interior Minister Søren Pind fended off criticism following reports that Denmark was planning to reinstate controls along its border with Germany and Sweden.
The minister said that the measures being proposed concerned the strengthening of customs controls in order to counter criminal activity by organised gangs, and promised that Denmark would continue to respect the rules of the Schengen agreement.
Commissioner Malmström told journalists that she was not able to comment on either the measures proposed by the Danish government or the assurances given by Minister Pind.
She said that the Commission would need some time to examine the proposals that her office had received from Copenhagen late on Wednesday afternoon (11 May).