Funny. Have you read the YouGov poll that article cites as a source for most of its claims?
It actually states that there is LESS antisemitism in the Labour party than there is in the Conservative party, and Brexit supporters are more likely to be antisemitic than Brexit opponents (Page 6):
"Analysis of the data shows patterns that remain consistent each year, pointing to specific areas of concern. This provides a valuable resource to Campaign Against Antisemitism and other organisations combatting antisemitism which wish to target their outreach work effectively. For example, men are much more likely to be antisemitic than women, older people are much more likely to be antisemitic than younger people, and people of lower social grades are more likely to be antisemitic than people of higher social grades. Our data also revealed patterns in antisemitism across political divides, with supporters of left-wing political parties and supporters of the ‘remain’ camp in the EU referendum all less likely to be antisemitic than those on the right or supporters of the ‘leave’ camp."
It also says this (Page 19 - emphasis theirs):
"Only 4% of British Jews feel that no UK political parties tolerate antisemitism. By comparing these responses with the data from the polls of the British population that we commissioned YouGov to undertake, we can pinpoint the problem. The YouGov data shows, for example, that Labour Party supporters are less likely to be antisemitic than other voters, so the cause of British Jews’ discontentment with the Labour Party must be the way that it has very publicly failed to robustly deal with the antisemites in its ranks. This means that the Labour Party has fallen out of step with its core supporters, who are generally less likely to hold antisemitic beliefs."
SOURCE: https://antisemitism.uk/wp-content/uploads/2017/08/Antisemitism-Barometer-2017.pdf
In other words, all this really shows is that people FEEL there is more anti-semitism in the Labour party (which isn't surprising considering the recent scandals and how viciously papers like the Daily Mail were quick to leap on them and spread mistrust) when the facts show that the reverse is actually true. It's yet another example of the Daily Mail being extremely selective in their facts and skewering their stories to manipulate their gullible readers who won't even bother to check the contests of the sources they cite.
I notice you glossed over the elephant in the room.
British Jews ranked Islamism as their greatest concern, followed by anti-Semitism on the far-left, and then anti-Semitism on the far-right.
In both 2017 and 2016, we asked British Jews to rank different forms of extremism in the order that they concerned them. Their responses showed a clear hierarchy of concern, ranking Islamism as the greatest concern, followed by far-left and then far-right extremism.
It was also clear that the majority of British Jews are only concerned about anti-Semitism originating from Islamism, the far-left and the far-right, in that order.
In 2017 and 2016, the overwhelming majority of British Jews felt that political events had caused anti-Semitism to rise.
Read in the context of other answers, this could be linked to perceived tolerance of anti-Semitism in the Labour Party.
We have observed discourse about Israel being used as a disguised vector for anti-Semitism by Islamists, the far-left and the far-right, and it is extremely clear from these responses that British Jews are being victimised by those who cross from mere criticism of Israel into anti-Semitism.
Labour has 'anti-Semitism issue' - peer
