No deal was reached between British Prime Minister David Cameron and European Union president Donald Tusk Sunday in talks to agree changes to Britain's membership of the bloc ahead of an in-or-out referendum.
No deal yet. Intensive work in next 24 crucial. #UKinEU
— Donald Tusk (@eucopresident) January 31, 2016
The meeting was seen as vital to finding agreement on Cameron's demands for measures to curb migration into Britain -- the most difficult of four areas he wants to renegotiate before holding a referendum on EU membership by the end of 2017.
Both sides need to agree the main points of a deal before other EU leaders iron out the details at a summit on Feb. 18-19.
If agreement is reached then, Cameron could hold the referendum as early as in June in a vote which will determine Britain's future role in world trade and affairs, and also shape the EU.
A source close to the talks said they had reached agreement only on one of the four areas, while a spokesperson for Cameron said Britain had won "a significant breakthrough" by persuading the EU to say that the British leader could trigger an "emergency brake" on welfare payments to migrants immediately.
"On welfare, the commission have tabled a text making clear that the UK's current circumstances meet the criteria for triggering the emergency brake," the spokesperson said in a statement, adding that Britain was also keen to close "backdoor routes" into Britain.
The spokesperson said Tusk planned to circulate a draft text to all member states on Tuesday and that, before then, officials would meet in Brussels to "work through the day to resolve the outstanding issues".
Finding a way to curb migration has proved to be the most troublesome element of Cameron's renegotiation, which also seeks to address voter concerns over competitiveness and sovereignty.