English, Please!
For your information, every time I visit my father's family in Lapurdi (a region in France) I am surpirsed to hear the wonderful English coming out of the cashiers' mouths. In the EU everyone, literally EVERYONE, MUST learn English now in school, starting during 3rd grade.
Making English the official speak will not curve immigration. In fact, it will only create more illegals. Realize that.