Generally speaking, the British left has been on the side of the disadvantaged and the oppressed. For this reason, socialists, radicals and liberals have instinctively rallied to the cause of newcomers in an increasingly multicultural society. But circumstances have changed and the waters now are muddied. This lecture will explore the reasons why it is difficult for the left today, given its origins and orientations, to deal with Muslim and Jewish difference when that difference is asserted by Jews and Muslims themselves. (This paper was given on 16 May 2013 at the German Historical Institute London as part of the European Leo Baeck Lecture Series London, 2013.)