What are the range of views of the European far-right on the issue? It would seem that anti-Islamism would cause kneejerk support for Israel, but it would appear that other parties harbor anti-semitic elements as well. I'm guessing that the Dutch far-right (Fortuyn before he died, Wilders) is probably more pro-Israel than, say, the FN in France.
I think that the more far-right the far-right is, the more it tends to be anti-Israel. For example, the National Democrats in Sweden are very anti-Israel and anti-US. The Sweden Democrats, on the other hand are quite favourable to Israel.
(for those who don't know, the Sweden Democrats are the xenophobic party in parliament while the National Democrats are the splinter group who broke out because the Sweden Democrats sold out their core values of preserving Sweden Swedish, etc).
Basically, the modern far-right movement which is essentially just anti-Islam tends to be more pro-Israel. The more old-fashioned far-right movement is still Nazis and thus hate the Jews.