[BRUSSELS] Prime Minister David Cameron said on Friday he would seek an agreement to change European Union treaties at some point in the future as part of his renegotiation of Britain's membership.
"What is being discussed here is a substantial package of changes including treaty change that needs to be agreed before there is a British referendum," Mr Cameron told reporters after an EU summit in Brussels.
Previously British ministers have said they needed treaty change as part of the renegotiation, words that had been interpreted by some as meaning Mr Cameron wanted to complete the long process of treaty change by the end of 2017.
"It is the agreement of treaty change - that must happen. But it was never going to be the case that you would get all 27 other parliaments to pass treaty change before you have your referendum," Mr Cameron said.
"It is the agreement that will be the difficult thing to get - no doubt about it," he said.