Danyaal Mahmud had no idea far-right activist Tommy Robinson, real name Stephen Yaxley-Lennon, was due to be campaigning in Warrington last month.

The 23-year-old apprentice was in the North West town for an appointment when he was invited to join protestors awaiting Yaxley-Lennon’s arrival.

“I was the only Asian person there. All these people from [United Against Fascism] kept hugging me and telling me I was brave to be standing with them,” Mahmud later told the Observer newspaper.

Within seconds, Yaxley-Lennon – who is standing to be one of the region’s members of the European Parliament – sought Mahmud out. 

“The first time he approached me, he asked me if I thought he was racist and I said: yeah,” Mahmud explained. “Then he says: ‘do you know 80% of grooming gangs are Muslim?’ I go to him, ‘that’s a false statistic there, what about white paedophiles? Why are they not called Christian grooming gangs?’ – and then he goes off on one.”

All the while, Mahmud was holding a McDonald’s vanilla milkshake he’d bought earlier. It was, he claimed, a total coincidence.

Yet, after hurling the dairy drink over Yaxley-Lennon, Mahmud unwittingly created a lasting image of the Euro elections and perhaps even political protest more generally in 2019.

The reasons why people gravitate towards food when plotting a political protest is often “a matter of convenience”, according to Dr Benjamin Franks, an academic in anti-political action at the University of Glasgow.

“Throwing food has frequently been a sign of disrespect – take the lobbing of rotten fruit at miscreants placed in the pillory or stocks,” he told HuffPost UK.

“In the political, and anti-political, context a variety of foodstuffs have been used, which are largely a matter of convenience.

“The feminist attack on Miss World in 1970 used eggs and flour, whilst the Biotic Baking Brigade reverted to the tradition of the custard pie.”

Dr Franks said that the first use of the milkshake on Yaxley-Lennon “was probably a matter of convenience, but its effectiveness and symbolic power caught on”.

“The prevalence of the milkshake is new,” he added. “This is partly because it is now a staple of fast food restaurants and thus easy to get hold off at short notice.

“Second, because the alt-right used milk as symbol, for purity, whiteness and to mock the frequency of lactose intolerance in some targeted minority groups.

“Third, it is highly effective. It makes the target uncomfortable and look ridiculous. The great leader reduced to the status of a slapstick stooge by a children’s drink.”

“Opponents of this intervention rightly point out that although comical, throwing a milkshake is a form of violence,” Dr Franks added. “However, it needs to be borne in mind that it is a very minor form of violence.”

Since Mahmud drenched Yaxley-Lennon, the former English Defence League leader has been soaked once more, and milkshakes have also been hurled at Brexit Party leader Nigel Farage in Newcastle and Ukip candidate Carl Benjamin.

Farage was splashed within 21 minutes of arriving in the North East city while Benjamin, a Ukip South West MEP candidate, has been the victim of numerous attempted milkshake attacks, including one in Salisbury on Sunday which left him covered in the liquid.

A scuffle also broke out in Truro, Cornwall, when two protesters tried and failed to throw the drink at him.

Benjamin, who also goes by his YouTuber name Sargon of Akkad, had become notorious for comments about raping Labour MP Jess Phillips.

So-called “milkshaking” has become so common that a McDonald’s branch in Edinburgh was asked to stop selling the drink when Farage made a campaign visit last week.

McDonald’s rival Burger King later tweeted: “Dear people of Scotland. We’re selling milkshakes all weekend. Have fun. Love BK.”

Some have welcomed “milkshaking” with gusto and championed culprits as “everyday heroes”. The hashtag ″#SplashTheFash” has been adopted on social media and local ice cream parlours even offered discounts ahead of political events.

And a doctored Banksy-style image showing a protestor hurling a McDonald’s shake with the caption “The revolution will be pasteurised” went viral on Twitter.

Yet despite its celebration by some, police have made clear they believe the act is an offence, and have arrested at least two milkshake throwers on suspicion of common assault over the past few weeks.

And Downing Street has said it supports efforts to “stamp out [the] unacceptable and unlawful behaviour”.

A spokesperson added: “The prime minister has been clear that politicians should be able to go about their work and campaign without harassment, intimidation or abuse.”

But before ‘milkshaking’ became a verb, recent political history provides a few memorable examples of other foodstuffs being chucked at politicians.

In 2001, then-deputy prime minister John Prescott notoriously punched a man who threw an egg at him in Rhyl, Wales.

Labour leader Jeremy Corbyn was also hit with an egg by a Brexit supporter who shouted “Respect the vote” as he struck him at the Muslim Welfare Centre in Finsbury Park, north London, in March.

And Tony Blair was dusted with purple flour when demonstrators threw it into the Commons chamber during Prime Minister’s Questions in 2004.

However, the sudden emergence of the milkshake has already made politicians weary.

After being soaked by the £5.25 banana and salted caramel number from high-end burger joint Five Guys this week, Farage could be heard quizzing his team about missing the threat.

“How did you not spot that?,” he asked as the white liquid slowly dripped off his jacket.