Tusk: No consensus on UK's immigration demand

"Our goal is to find solutions that will meet the expectations of the British prime minister, while cementing the foundations on which the EU is based," European Council President Donald Tusk wrote in a letter to EU leaders on Monday.

British Prime Minister David Cameron in November highlighted four areas for reforms in order for Britain to remain in the bloc. The most significant among them is the demand for restrictions on the freedom of movement with the EU.

Tusk, the former prime minister of Poland, said they would discuss all these issues in next week's summit in a bid to iron out "substantial political differences" before coming out with a concrete proposal by February.

"Uncertainty about the future of the UK in the European Union is a destabilizing factor. That is why we must find a way to answer the British concerns as quickly as possible," he said.

Britain's 'contentious' demand

Cameron has proposed that welfare benefits be denied to EU citizens working in Britain for the first four years of their stay. This proposal is at loggerheads with one of EU treaty's obligations of not discriminating among the citizens of the bloc.

The referendum over the UK's future in the EU is expected by 2017. Cameron has said the reforms would allow him to campaign for staying in the union.

Following his meeting with Tusk last month, Cameron said he expects a "substantive discussion" on his demands with fellow EU leaders in next week's summit.