It will be hard for officials renegotiating Britain’s EU membership to meet a goal of having a framework ready for discussion at a regional summit next month, a senior EU official involved in the talks said on Wednesday. Prime Minister David Cameron is trying to win concessions from other leaders ahead of a referendum on British membership promised by the end of 2017. With opinion polls showing Britain sharply divided over whether to stay or leave, the outcome of the vote will determine the country’s future role on the global stage as well as shaping the European Union, which has struggled to maintain unity over migration and financial crises. The British government wants at least the bulk of a deal to be ready for European Union leaders to endorse at their next meeting on Dec. 17-18, but officials and diplomats fear there may not even be a narrowing of differences by then. Meeting that target date would be difficult, Jonathan Faull, the EU executive’s point man in negotiations between Britain and its partners, told an Irish parliamentary committee meeting. He noted “the complexity of some of these issues and the relatively recent date on which the Prime Minister sent his