No, on reflection Jim, he does have a valid point. If we follow his reasoning as above, IE

Labour had 515,000 members, if your percentages are representative that means that 128,750 of them hold some anti-Semitic view.
The SNP had 120,000 members,if your percentages are representative that means that 30,000 of them hold some anti-Semitic view.
The Liberal Democrats had 76,000, if your percentages are representative that means that 19,000 of them hold some anti-Semitic view.
The Green Party (England and Wales) had 55,500, if your percentages are representative that means that 13,875 of them hold some anti-Semitic view.
UKIP had 39,000 members of whom 39% hold some form of view that could be termed anti-Semitic which would produce a number of 15,210.
Plaid Cymru had 8,300, if your percentages are representative that means that 2,075 of them hold some anti-Semitic view.

As of December 2013 (latest published figure) the Conservative Party had 149,800 members. If your percentages are representative that means that 37,450 of them hold some anti-Semitic view.

And then turn that round to those who are NOT antisemitic we get the following figures.

Number of member who are not antisemitic -

Labour - 386250
Conservative - 110550
SNP - 90000
LibDem - 57000
Green - 41125
UKIP - 23790
Plaid Cymru - 6225

So, Labour has 3 times as many members who are not antisemitic than it's nearest rival, the Conservatives and 60 times more than Plaid Cymru.

So, by Teribus's reckoning, The Labour party have the best record which makes Plaid Cymru look like something from 1930s Germany. And yet Labour are still being castigated for trying to make that number even higher. Very odd.

BTW Teribus, you may note that I am using your chosen name. I note your attempt to belittle me (pun intended) by referring to me as 'Gnome'. It doesn't work. As you don't seem to have worked it out, I think I had probably tell you that I am not really a Gnome :-)

Cheers

DtG