Some forms of antisemitism are self-evident in their manifestation: neo-Nazis wielding swastikas, denial of the Holocaust, vile sentiments known as the “blood libel”, which suggest that Jews harvest the blood of Christians with which to celebrate religious festivals year on year. Most of us would recognise these as bigoted and hateful, an attack on a community that has for centuries experienced prejudice across the world.

In the days that have followed Jeremy Corbyn’s offensive Facebook post coming to public attention, there has been outrage from what appear to be two distinct camps. Some Labour members are deeply troubled by the situation, while others argue ignorantly that the Labour leader has done nothing wrong.

What has become obvious in the past few days, however, is that many simply do not understand the content of this mural and why it is so deeply offensive – this is a more subtle antisemitic sentiment, which takes contextualising to understand.

Considering the Jewish community makes up just 0.5% of the UK’s population, and that for many of us the closest we will have to an education in the history of discrimination faced by Jewish people amounts to a few months of GCSE history and Inglourious Basterds, it’s possible a simple explanation could rectify the confusion once and for all.

First, make sure to actually look at the mural. Don’t take a fleeting glance as you prepare to tweet your outrage, but pause for a moment and take it all in. Sitting around a table is a group of rotund men: one has a full beard, and is counting money. That, in and of itself, is an antisemitic symbol.

It’s not just the big, hookednoses and evil expressions that make this iconography offensive and troubling, these depictions mirror antisemitic propaganda used by Hitler and the Nazis to whip up hatred that led to the massacre of millions of Jews. This extends to the table these figures are sat at, resting on human bodies, as the Nazis also depicted.

Context here is also important. If you haven’t yet, then research The Protocols of the Elders of Zion. An entirely fabricated text printed first in Russia during the early 1900s, it purports to document a meeting of Jewish leaders setting out plans to take over the world by controlling the media and press, and fostering religious conflict to subjugate non-Jews across the globe.

There is more than a visual connection in this mural to antisemitism – the messaging is full-blown Nazi too

During the 1920s and 1930s the Protocols were a key element of the Nazi propaganda programme – at least 23 editions were published by the party in the two decades that preceded the outbreak of the second world war in 1939. The domination of the world by hooknosed men wielding power and money? There is more than a visual connection in this mural to antisemitism – the messaging is full-blown Nazi too.

In other contexts Illuminati conspiracies are light-hearted and funny: it’s not antisemitic to joke that Kanye West and Taylor Swift are part of a secret, triangle-based plot to conquer the world. But the employment of an Eye of Providence symbol (often associated with the Illuminati and Freemasonry) in the offending mural is clearly antisemitic. Racist conspiracy theorists also long claimed that Jews are in control of the Freemason network – think the Rothschilds and George Soros. That is antisemitism too.

If you’re left in any doubt, just read the words of Mear One, the street artist who painted the mural: “Some of the older white Jewish folk in the local community had an issue with me portraying their beloved #Rothschild or #Warburg etc as the demons they are,” he has written.

Of course there are some people – within Labour and outside of it – who are pleased to have any excuse to attack Corbyn. Their motivation might be unpleasant, but the “weaponisation” of antisemitism is somewhat less troubling if it can perceived to be there in the first place.

A small handful of people in Labour’s ranks know only too well the connotations in this mural, yet continue to defend it. There is no space in the Labour party for you. Progressive organisations are better off without you inside.

Labour can’t just pledge to kick the antisemites it finds out of the party: it needs to make a plan for combating bigotry in opposition and for entering government too. The Chakrabarti report from 2016 into antisemitism in Labour must be implemented fully. A party bureaucracy that has slowed the process down cannot be allowed to do so any longer. Labour must pledge to improve the national curriculum – better political education is needed in schools across the country to ensure murals like this are understood for what they are.

There must also, starting now, be better investment in educating Labour’s 550,000-strong party membership. A party that prides itself on its commitment to equality can and must do better.

It’s somewhat understandable that some people jumping to Corbyn’s defence now do so as a kneejerk reaction, as years of smears have made members defensive. This, however, is no such nonsense.

Corbyn is no antisemite, but he displayed a lack of judgment and awareness that he – and it appears some members – need to address. Time must be taken for reflection and education, or it will prove impossible to ensure the left is never blind to this issue again.

• Michael Segalov is the news editor of Huck magazine