The UCU wants to dump the EUMC definition of anti-Semitism, which says (among other things) that the use of double standards to criticize Israel, and the use of mendacious, dehumanizing, or stereotypical charges against Jews as a collective, including but not limited to stereotypes such as the myth of Jewish power in controlling the media, economy, government or other societal institutions, could be anti-Semitic, as could the drawing of comparisons between contemporary Israeli policy and that of the Nazis.
Now there are three, and only three, possibilities with respect to anti-Semitism for allegations such as are mentioned in the EU definition. The first possibility is that all such allegations against Jews are invariably anti-Semitic. The second possibility is that all such allegations may be anti-Semitic – i.e. sometimes they are, and sometimes they aren’t. The third possibility is that such allegations are never anti-Semitic. The EUMC account of anti-Semitism goes for the second possibility: such charges may be anti-Semitic (or they may not, depending on context). That’s what the UCU Executive wants to deny.