British Prime Minister David Cameron said on Friday that European Union reched a reform deal that would give Britain "special status" in the bloc and that he would recommend it to his top team of ministers.
"I have negotiated a deal to give the UK special status in the EU. I will be recommending it to Cabinet tomorrow," Cameron said on Twitter.
I have negotiated a deal to give the UK special status in the EU. I will be recommending it to Cabinet tomorrow. Press conference shortly.
— David Cameron (@David_Cameron) February 19, 2016
European Council President Donald Tusk said an agreement to keep Britain in the bloc won unanimous support from all of the EU states 28 leaders.
"Deal. Unanimous support for new settlement for #UKinEU," Tusk wrote on Twitter.
Deal. Unanimous support for new settlement for #UKinEU
— Donald Tusk (@eucopresident) February 19, 2016
Cameron said he would campaign with all his "heart and soul" for Britain to stay in the European Union.
At a news conference, Cameron said the deal had delivered what he promised British voters when running for his second term and would recommend the agreement to his cabinet on Saturday. He said he would set a date for a referendum soon.
"The British people must now decide whether to stay in this reformed European Union or to leave. This will be a once in a generation moment to shape the destiny of our country," he said.
"I believe that this is enough to recommend that the UK remain in the EU having the best of both worlds."
The British prime minister also said he would offer new proposals to strengthen the country's sovereignty - a clear bid to try to keep the more sceptical lawmakers in his Conservative Party on board with his campaign to keep Britain in the bloc.
The deal was reached late on Friday after the EU's two top figures,Tusk and Jean-Claude Juncker, presented its 28 leaders with draft proposals at a long-delayed dinner.
It came after France, Belgium and eastern European countries dug in their heels over changes to areas including regulation for non-eurozone countries and benefit payments to EU migrants for four years.
He said Britain would now be "permanently out of ever closer union", one of the EU's founding principles, while Britain would be able to apply "tough new restrictions on access to welfare."
European leaders have agreed on a "fair compromise" deal with Cameron, with which he can campaign to keep Britain in the bloc, German Chancellor Angela Merkel said at the conclusion of an EU summit.
"We believe that with this we have given David Cameron a package with which he can campaign in Britain for Britain to stay in the European Union," Merkel told reporters at the end of the two-day summit.
Cameron is now expected to return to London where, after a cabinet meeting at 0900 GMT on Saturday, the referendum campaign will whirr into life as ministers who want Britain to leave will be allowed to speak out for the first time.
Opinion polls suggest the British public is finely balanced on whether to back a Brexit.