Britain's referendum on European Union membership could go either way, polls indicated on Tuesday, two days from a vote that could determine the political and economic fate of Europe. With time running out to convince voters, an audience of thousands will gather in Wembley Arena for a debate between the two camps, featuring the former mayor of London Boris Johnson for "Leave" and his successor Sadiq Khan for "Remain." The latest polls were split, with two suggesting the "Remain" side was ahead but a third indicating the "Leave" camp could prevail in the June 23 vote. All signs "point to a referendum that will truly come down to the wire," political strategist Lynton Crosby wrote in the Daily Telegraph. "The referendum outcome is uncertain. I wish Britain the best," he added. The surveys were mostly conducted after the shock murder of Jo Cox, a 41-year-old Labour lawmaker and mother of two, who was shot and stabbed on the way to meet members of the public in northern England last week. Her alleged killer, 52-year-old Thomas Mair, gave his name as "Death to traitors, freedom for Britain" on his first appearance in court after being charged with her murder. The anti-EU UK Independence Party is due to reveal a new poster, after critics accused their previous billboard — showing lines of migrants walking across Europe with the words "Breaking Point" — of stirring hate. As the voting day of June 23 nears, a series of prominent figures have offered their takes on the referendum. The author of the Harry Potter series J.K. Rowling called it "one of the most divisive and bitter political campaigns ever waged," while Ireland's Prime Minister Enda Kenny warned Brexit could disturb a hard-won peace in Northern Ireland. Business magnate George Soros, who famously profited by betting against the British Pound in a 1992 currency crisis, predicted that a vote to leave the EU could trigger a sterling crash. "A vote to leave could see the week end with a Black Friday, and serious consequences for ordinary people," Soros wrote in the Guardian. The pound has been on a see-saw as the referendum approaches and slipped again on Tuesday. It had risen to a three-month peak the day before as surveys indicated narrow gains for the "Remain" camp. A study released Tuesday showed the "Remain" side with a six-point lead on 53 percent, using a methodology that adjusts the data according to how likely respondents are to vote. Nevertheless, the researchers NatCen emphasized that a 50-50 result was still within their survey's margin of error. "It is important to remember that the outcome looks so close that any lead should be treated with caution," NatCen senior research fellow John Curtice said in a statement. Two newspapers, the Guardian and the Daily Telegraph, used their Tuesday front pages to endorse opposite sides of the campaign. "The EU embodies the best of us as a free people in a peaceful Europe," urged The Guardian. "Vote against a divided nation that turns inwards. Vote to remain." In contrast, the Daily Telegraph implored readers to back Brexit. "A world of opportunity awaits a fully independent United Kingdom," it argued. "If this Thursday's referendum is a choice between fear and hope, then we choose hope." The British referendum has opened the prospect of other nations demanding a vote, too, perhaps placing in peril the very survival of the European project, which was born out of a determination to forge lasting peace after two world wars. Labour leader Jeremy Corbyn, who is campaigning for "Remain," told a television audience that voters "may well" vote to leave, but that the EU had to reform either way. "If we remain, I believe Europe has got to change quite dramatically to something much more democratic, much more accountable," Corbyn said. The president of the EU, Donald Tusk, indicated he was taking stock. "Whatever the UK vote is, we must take a long hard look on the future of the Union," Tusk wrote on Twitter. "Would be foolish to ignore such a warning signal."