the ukip leader was booed by voters at westminster 's methodist central hall as he faced claims he blamed all of britain 's problems on migrants .
pollster icm , which was hired by the bbc to select the audience members , today defended its process ` using random location selection techniques ' .
nigel farage today insisted he did not ` lose my rag ' after rounding on the audience of a live tv debate for being too left wing .