On a bright sunny day in the English market town of Totnes, an angry man with a beard is dripping with milkshake. Like a victim of a seagull-based atrocity, his hair is slick with the pinky-white drink, which drips into his beard and covers his black T-shirt. As protesters yell around him, he tries to put his sunglasses on against the glare, but thinks better of it. Presumably they’re covered in milkshake too.

This is the third “milkshaking” of Carl Benjamin, Ukip’s controversial MEP candidate for the southwest – an anti-feminist YouTuber known as Sargon of Akkad – in three days. He has made headlines by refusing to apologise for tweeting “I wouldn’t even rape you” at the Labour MP Jess Phillips (even adding to his comment last month on YouTube: “I suppose with enough pressure I might cave, but let’s be honest nobody’s got that much beer”). He has also defended using the n-word, saying he finds “racist jokes funny”, and his videos contain other slurs (including “retard” and “faggot”).

On the campaign trail in Cornwall, two protesters threw milkshake at Benjamin in Truro (they missed), and his Ukip campaign bus received a drenching in Plymouth.

By the time he reached Totnes in Devon, a local ice cream parlour called Delphini’s was urged by police to withdraw its “tongue in cheek” 99p milkshake offer. Benjamin got drenched anyway, and the culprit was arrested.

Exchanging more classic tools of political protest – ie. the humble egg – for milkshake stems from the viral video of a man in Warrington chucking a McDonald’s milkshake over the head of far-right thug Stephen Yaxley-Lennon, aka Tommy Robinson.

Robinson is running as an independent candidate in the north-west, and the incident was his second milkshaking in two days, after he had one lobbed at him in Bury, Greater Manchester.

Both, it has been reported with laudable attention to detail, were strawberry.

Why is this now the food of choice for political protest?

A variety of foods have been used over the years in protest, including eggs and custard pie, and it’s usually “a matter of convenience”, says Dr Benjamin Franks, a senior lecturer in Social and Political Philosophy at the University of Glasgow who specialises in direct action.

“Nowadays, carrying raw eggs to a nationalist meeting would require some backstory to justify it if challenged by the police. Carrying a milkshake – previously – did not,” he says.

“I think it [milkshake] latterly caught the imagination of anti-fascist protestors because it can be carried without raising suspicion and is clearly effective in making the victim feel uncomfortable and look ridiculous,” he adds. “The enemy of the far-right can be – and is – everywhere.”

Nowhere is this clearer than online, where the well of milkshake mania oozes thick. Slogans are appearing (“The Revolution will be Pasteurised!” and “Lactose Against Intolerance!”), and there’s a social media campaign called “Milkshakes Against Racism”, encouraging the practice, and even aiming to fund it with a JustGiving page (“Depending on how much is raised, we may consider hiring coaches/paying for travel to events!”).

“Today’s politics are hugely performative,” says Dr Ivan Gololobov, a politics teaching fellow at the University of Bath who specialises in radical youth subcultures and anti-politics.

“Street action itself is worth almost nothing if it does not have an online follow-up. Milkshake on a figure who pretends to be serious and well-established has become an incredibly powerful image destroying the platform of seriousness for the likes of Robinson and Benjamin.”

He describes throwing milkshake as a “highly captivating non-violent alternative” to a punch, and calls it a “spontaneous reaction to a bully on the street” that has become a “form of direct action… a synonym for counter-protest against far-right views”.

Milkshake is also a universally-loved fast food guilty pleasure; an “everyman” choice. The Observer reporter who tracked down the original viral milkshaker, Danyaal Mahmud, described him as an “everyday hero”.

Part of its appeal seems to be the innocence and fun associated with the drink, particularly the pink variety – a pleasing contrast with the darkness its targets represent for many.

“Who drinks milkshake? Kids and teenagers,” says Dr Gololobov. “Milkshake on a fancy suit of an upper middle-class bigot symbolises how fake their bravado is and how irrational their arguments are – not far from school bullying. And what is the best way to stop the bully? It is to show them their place.”

There could be a deeper significance too. The alt-right has been known to use milk as a symbol of white supremacy, because of its “whiteness”, and in order to mock people with a “genetic predisposition” to lactose intolerance, says Dr Franks.

“The milkshake is turning that symbol against them,” he tells me. “It is an example of political ju-jitsu. It also makes them look foolish, undermining their self-image of power and control. The bathos of the great leader brought low by a drink associated with children is highly effective.”

Milkshaking hasn’t been embraced by all Robinson and Benjamin’s opponents, however. Organisers of a rival rally that day in Totnes distanced themselves from the milkshaker (who wasn’t part of their group, called Totnes Together Against Hate), and advertised milkshakes at their own event as “shaken, not thrown”.

“We were stood there, we had our placards and we were chanting and singing and everything else, then all of a sudden one guy runs up behind him and pours a milkshake over his head,” says Josh Adams, 28, a customer services coordinator and member of the local Totnes Labour party who was present at the most recent milkshaking of Benjamin.

“The immediate backlash and everything I’ve heard since is that we are a hate group, that we condone violence… [But] we had no knowledge that was going to happen, and apparently the guy wasn’t local.”

His fiancé Lauren and other Labour members organised their alternative event two minutes from where Benjamin was campaigning in the Civic Square. They amassed 150 people and ended up marching to protest against the Ukippers down the road.

They told their group beforehand to avoid throwing milkshake.

“It isn’t something we condone. We understand people’s reasoning, but our event was designed and advertised and set up to be a peaceful protest,” Adams says. “The biggest factor for us was there was no conflict there, it was to show we aren’t thugs, we aren’t violent, we just wanted to make our views known in a peaceful way – very much us deploring his views and showing that Totnes is a tolerant town.”

With police involved, candidates’ supporters have been given the opportunity to claim “violence” and “assault”. But their cries over spilt milk have also been revealing.

Robinson’s first reaction was a windmill of punches at Mahmud when he was doused, and an associate at one of his later rallies in Middleton confiscated a McDonald’s drink off someone. Another supporter at the rally harangued a young man about his McDonald’s milkshake, asking to see its contents, commanding him to drink it, and threatening to “knock your teeth out”.

Although Benjamin’s response was to sip a milkshake on the next leg of his southwest tour in Exeter, other Ukippers have been less relaxed.

“Just to be clear, anyone that comes at me with a milkshake will need the straw to eat their meals for the next few months,” tweeted Ukip activist and darling of the alt-right Mark Meechan (or Count Dankula, infamous for his video teaching a dog Nazi salutes by repeating “Want to gas the Jews?” at it). “I don’t care how many cameras are rolling, you’ll be getting booted up and down the street.”

A significantly more aggressive response than that of the People’s Milkshaker, Danyaal Mahmud, who told the Observer he’d be willing to make amends with Tommy Robinson. “I guess we could shake on it,” he said.