Paul Crowther, 32, launched the banana and salted caramel milkshake over the ex-Ukip leader while he was campaigning in Newcastle upon Tyne on May 20.

The married former Sky employee has been dismissed following the incident, North Tyneside Magistrates' Court was told.

He admitted assault and criminal damage to a lapel microphone on Farage's suit.

District Judge Bernard Begley, who told Crowther he had carried out an "act of crass stupidity", ordered him to carry out 150 hours of unpaid work

After the prosecution suggested Crowther should pay compensation to have the suit cleaned, the judge ordered him to pay Mr Farage PS350 ($A641).

James Long, prosecuting, said: "I suppose for the split second the attack took place, Mr Farage would not know whether it was a harmless liquid or something, in this day and age, far more sinister."

He said it was clear from a Facebook posting before the incident that Crowther intended to throw milkshake on the politician.

It took 20 minutes for a police van to take him away after he was arrested, and Crowther was interviewed by journalists.

At the time he justified his actions, saying he did not regret it and that "the bile and racism" spouted by Farage was far worse than having milkshake poured on him, the court heard.

He later told police when he was interviewed that it was a "moment of madness", "a loss of control" and he watched himself do it.

Brian Hegarty, defending, said there was a long history of protesters throwing food at politicians going back hundreds if not thousands of years, although the items may have changed from fish, to fruit, to eggs and on to milkshakes.

He said Crowther now regretted his lunchtime actions, saying: "The defendant has had cause to reflect and, having done so, he would say he wished he would not have acted as he did."

Since the incident he has suffered from repeated threats of violence and has had regular police checks to his address in Throckley, Newcastle, the judge was told.

Australian Associated Press