On November 10, two police officers informed Pearson that she was under investigation and invited her for a voluntary interview following an allegedly offensive tweet a year ago.

She is being investigated under section 17 of the Public Order Act 1986, relating to material alleged to be “likely or intended to incite racial hatred”.

Pearson described the experience as “Kafka,” writing last week: “I was definitely shocked. Amazed. And this. Upset. How could I not be? It’s never nice to have the police at your door if you’re a law-abiding person, because the police at your door can only mean one of two things: tragedy or trouble.

“But to have them here at the saddest, most solemn meeting on the calendar with this kind of malevolent nonsense, it was surreal.”

Essex Police were attacked for his handling of the investigationfrom which it later emerged, and officers from the Metropolitan Police and Sussex Police. The Essex force set up a “gold squad”, usually reserved to deal with major crime, to investigate.

Sammy Wilson, the Democratic Unionist MP, said confidence in the police had been undermined by three forces being involved in the Pearson case, when officers failed to investigate ‘real’ crimes such as burglary, shoplifting and anti-social behaviour.

“At the same time, we note that three police forces spent a year investigating a columnist’s tweet. Certainly, if there is going to be police reform, one of the things we should do is tell the police that they are no longer the thought police,” he told MPs.

“They are meant to be a police force that deals with crime and if they are asked to change the stupid law brought in by the last government, will she make sure that is done so we don’t have any more of this nonsense? “