Chief Rabbi Ephraim Mirvis has issued a warning about the dangers of social media during a radio conversation about the “Nazi” slurs recently directed at Conservative MP Anna Soubry.

In an appearance on Emma Barnett’s Radio 5 Live show, the Chief Rabbi said he had watched the video clip – that went viral - of a group of protesters verbally abusing Ms Soubry “so many times”, saying he was “so saddened and also troubled by it.”

Asked by Ms Barnett if the use of the word “Nazi” by the demonstrators could be defended under free speech laws, the Chief Rabbi said: “Never, ever.”

In an apparent condemnation of the police’s failure to take immediate action, he said: “I’m so surprised that it was allowed to continue.”

He added: “Those people saying that – they obviously don’t know what Nazism is all about. And if they had said it knowing it, them that makes it all the worse.

“This is just an indication of some of the discourse that is taking place today and we cannot allow it to get out of control.”

In a significant intervention, the Chief Rabbi addressed the role of Twitter and other forms of social media in spreading hatred.

Admitting he regularly looked at his own Twitter account, which he said had left him the target of abusive messages, he said: “Today society is on a fast track from thought to publication.

“You think things, in a few moments you press a few buttons and globally it can be read.

“And these words are having an enormous impact on people. If only people would think better before they actually sent messages out. Because there is so much hate being expressed.”

The Chief Rabbi then cited the 19^th century Rabbi Israel Salanter, who had written of the need to exercise caution before speaking out.

Police are investigating whether any criminal offence was committed after Ms Soubry was branded a Nazi by Brexit protesters outside parliament earlier this month.

During a discussion on the BBC, people off-camera could be heard shouting “Soubry is a Nazi”.

Dozens of MPs wrote to the Metropolitan Police Commissioner to express their "serious concerns" about the "deteriorating public order and security situation" outside Parliament after the video of the confrontation, which was shared on Twitter, Facebook and elsewhere on social media, showed the police allowing protesters to insult the MP unchallenged.

Also during his appearance on Ms Barnett’s show on Monday, the Chief Rabbi was asked  about the continued impasse within the Labour Party over antisemitism.

The Chief Rabbi said he was “deeply concerned” the party was still failing to take “antisemitism seriously enough.”

He added: “There is a great backlog of cases that haven’t been dealt with.

“It took some time and some effort for the IHRA definition of antisemitism to be passed. 

“But we haven’t yet seen it being properly implemented so we continue to be very concerned in that regard.

“We  are still waiting to see and the longer we wait the more concerned we get. All we are asking for, all our society is asking for, is zero tolerance on antisemitism.

“There is tension between our community and  the Labour Party. There are well aware of that. This is nothing new .We are continuing to stress the end of talking and the need for action.

“They’ve said some impressive things but we need to see the results.”