Anti-zionism is NOT anti-semitism, at this point everyone with a passing interest in politics knows this and pretending otherwise is simply disingenuous and, frankly, vaguely libelous.
That said; Eurovision (voting favouritism aside) is supposed to be non-political, the whole point is that "normal people" (well... it's Eurovision... so not that normal, but you know what I mean) can come together and sing silly songs and dance about and laugh / cheer with each other, free from the day to day crapfest that is international politics. That applies to Mr Corbyn, AND to the press who are now apparently inclined to ****-stir

.