OXFORD, UNITED KINGDOM - MAY 14: Britain's Prime Minister David Cameron speaks at a "Stronger In" campaign rally at a school in Witney, on May 14, 2016 in Oxford, England. (Photo by Eddie Keogh - WPA Pool /Getty Images)
OXFORD, UNITED KINGDOM - MAY 14: Britain's Prime Minister David Cameron speaks at a "Stronger In" campaign rally at a school in Witney, on May 14, 2016 in Oxford, England. (Photo by Eddie Keogh - WPA Pool /Getty Images)