A generous social welfare system has long been at the heart of society in continental Europe and non-discrimination among EU citizens a cornerstone of the union.
Hence, the insistence of British Prime Minister David Cameron to deny some of those welfare rights to EU newcomers in Britain for up to four years has been a focal point of criticism.
"We have to approach this question of the social welfare system with a maximum of prudence, he said. "This is concerning Britain but it is also concerning the other member states."
European Council President Donald Tusk visited Romania today and insisted "we cannot and will not compromise on the fundamental freedoms and values. It is in this spirit that I drafted my proposal for a new settlement for the UK in the EU."
Juncker called the proposals that will be discussed at the summit as of Thursday "a fair deal for Britain and this is a fair deal for the 27 other member states."
Britain is demanding concessions before a referendum on whether the UK should leave the EU, a prospect known as "Brexit."
Cameron must hold a referendum by the end of next year. If a deal is clinched at the summit that starts Thursday, he might call a vote as soon as June.
Romanian Prime Minister Dacian Ciolos was in Brussels to discuss the issue, saying his country wants Britain to remain in the EU.
Juncker "knows, and I have said it several times, that Romania wants to find a solution for Great Britain to remain in the EU," Agerpres news agency quoted Ciolos as saying.
