BRUSSELS, Oct 15 (Reuters) - Anti-Semitism has no place in the EU, a spokesperson for the bloc"s executive Commission said on Friday, reacting to a tweet by Slovenian Prime Minister Janez Jansa that referred to Jewish U.S. financier George Soros and was criticized as anti-Semitic. "Social media should be a place for constructive and respectful debate. It should not be a place for personal attacks against individuals, be it private or public figures," the spokesperson told reporters in Brussels. "Anti-Semitism has no place in the European Union...It presents a threat not only to Jewish communities but to an open and diverse society."