Britain wants to change rules on free movement across the EU as it braces for a possible influx of Bulgarians and Romanians, Home Secretary Theresa May told European ministers on Thursday.
May, the interior minister, said in a speech to her counterparts in Brussels that free access to labour markets must not lead to "mass migration",according to the text of her address to the EU meeting.
Accordingly, countries should be allowed to impose a cap on numbers if European immigration reaches "certain thresholds".
Britain was caught off-guard by the numbers of Poles who came to work after the EU was enlarged to the east in 2004. By some estimates, one million lived in Britain at some point.
With controls on the movement of people from Romania and Bulgaria set to be lifted at the end of the year, London is concerned by the prospect of another mass influx.
Prime Minister David Cameron has suggested that citizens from EU countries including Romania and Bulgaria would not be able to claim out-of-work benefits for the first three months in Britain.
While Britain's approach has found an echo in some member states where immigration has become a sensitive political issue, others have reacted angrily, promising to defend what they see as a key principle of the European bloc.
European Employment Commissioner Laszlo Andor said that Britain was in danger of being perceived as a "nasty" country if it tried to limit freedom of movement.
Meanwhile, EU Justice Commissioner Viviane Reding tried to set out the middle ground Thursday, saying: "Free movement is a right but it comes with duties.
"Free movement is a right to free circulation; it is not a right to migrate in member states' social security systems," Reding said, according to the text of her address to the ministerial meeting.
Reding also outlined a five-point package to address concerns, among them a handbook on marriages of convenience and guidance on criteria to be used for establishing residence status and welfare entitlements.
Last week, Britain said of this EU response that it had "taken years of pressure" for Brussels to "finally acknowledge that free movement abuse is a genuine EU problem".
"But that is not enough. The Commission must listen harder and work with member states to bring forward meaningful solutions," a government spokesman said.
On Thursday, German Interior Minister Hans-Peter Friedrich was blunt.
"I say very clearly, we are not satisfied with the (EU) report, it is not sufficient to solve the problems," Friedrich said as he arrived for the two-day meeting.
"We will have to try to develop laws on a national level to solve the problem... if the Commission is not willing to support us in this matter," he added.
May said in a statement before the meeting that she planned to make clear "that I believe we need to change the way free movement rules work".