EU summit is make or break, president Donald Tusk says
European Union (EU) President Donald Tusk says the summit of 28 EU leaders to decide on the reforms that the UK is calling for will be one of the most important the bloc has ever seen.
With many core issues still outstanding going into the two-day summit, Mr Tusk said as he arrived for the opening session: "One thing is clear to me. This is a make or break summit, I have no doubts."
Mr Tusk said both sides were still "in the middle of still very difficult and sensitive negotiations" as the summit centre in Brussels started filling with political leaders and legal experts, who would have to pour any decision into binding legal texts.
Prime Minister David Cameron says he'll be "battling for Britain" but still faces hurdles in his talks on an EU deal.
Mr Cameron said he was fighting to close a deal by Friday but admitted "it's going to be hard".
He added: "If we can get a good deal I'll take that deal, but I will not take a deal doesn't meet what we need. I think it's much more important to get this right than to do anything in a rush."
Mr Cameron hopes the 28 EU nations can strike agreement on the changes Britain seeks to its relationship with the bloc, so he can call a referendum on UK membership for as early as June.
French President Francois Hollande warned European leaders against making too many concessions to the UK.
Mr Hollande said such a scenario could prompt other countries to seek "special rules" and undermine the principles of European unity.
He added: "I want Britain to stay in the EU. But I hope most of all that Europe can advance, can be stronger and that no chief of state could stop that."
German Chancellor Angela Merkel says she wants to do everything to help ensure that Britain stays in the bloc.
She added: "I'm going into this debate with the position that we would like to do everything to create the conditions so that Great Britain can remain part of the European Union."