The Commons Speaker has demanded police tackle the “aggressive, threatening and intimidating behaviour” towards politicians and journalists outside Parliament.
John Bercow hit out at “toxic attacks” in a letter to Metropolitan Police Commissioner Cressida Dick the day after MP Anna Soubry was branded a Nazi by a mob during television interviews.
He said he supported more than 50 MPs who also wrote to Ms Dick to express their “serious concerns” about the “deteriorating public order and security situation” outside Parliament”.
Scotland Yard said on Tuesday that officers near Parliament have been “briefed to intervene appropriately” if the law is broken, amid a visible increase in the police presence in Westminster.
The force is assessing whether any crime was committed by the protesters who hurled abuse at Ms Soubry and campaigners Owen Jones and Femi Oluwole on Monday.
In his letter to Ms Dick, the Speaker said: “It is, frankly, intolerable if Members of Parliament and journalists cannot go about their lawful business without being ritually insulted, abused, intimidated, threatened and harassed.
“There seems to be a pattern here of a regular coterie of burly white men who are effectively targeting and denouncing Members whom they recognise and dislike — most notably female and those from ethnic minority backgrounds.”
Mr Bercow added that he realised police had to balance the right to peaceful protest and intervention when things “turn sour”.
“However, it’s one thing demonstrating from a distance with placards, or calling out slogans – and another, where the protester invades the personal space of a Member, subjects him or her to a tirade of menacing, racist, sexist and misogynistic abuse, and follows them back to their place of work,” he went on.
“I politely suggest that the present situation is not only intolerable but untenable.”
Speaking in the Commons as the letter was published, Mr Bercow described the intimidation as “a type of fascism”.
Ms Soubry told Good Morning Britain on Tuesday that there was a small group of people “roaming around Westminster intimidating people going about their lawful business”.
The Tory MP for Broxtowe added that, while she anticipated a level of criticism and abuse as an MP, she expected authorities to act when it “crossed the line”.
She told GMB: “It crossed the line in December, it was journalists who were being attacked.
“(Sky News’ political editor) Faisal Islam, who is male, was racially abused by these people, it’s the same group, all on video, and the policy of the Metropolitan Police is to ignore it.”
Protesters could be heard chanting “Soubry is a Nazi” as she appeared on BBC News, prompting her to tell interviewer Simon McCoy: “I do object to being called a Nazi, actually.
“I just think this is astonishing, this is what has happened to our country. But let’s try and move on and be positive about things.”
Protesters also chanted slogans including “Liar, liar” throughout a live interview with Ms Soubry on Sky News.
Earlier on Monday, political commentator Owen Jones shared a video on Twitter which showed him being accosted by a group outside Parliament, including men wearing Union flags.
They could be heard calling him a “traitor” and a “horrible little man” and accusing the Labour activist of writing “fake news”.
The incidents prompted a wave of criticism from politicians and commentators from across the political spectrum.
A senior Met Police leader said officers would be expected to intervene if protesters tried to stop MPs going about their daily routines.
Asked if the Met would take specific action over Mr Bercow’s concerns about the safety of MPs moving to and from Abingdon Green, Deputy Assistant Commissioner Laurence Taylor said: “It’s one of the allegations that we are assessing at the moment to determine whether any criminal activity has taken place.
“We’ve given a very clear direction to our officers on the ground that if they witness criminal behaviour then there is an expectation that an arrest will be made.
“And also if they witness any behaviour that is intimidating, or to an extent that it is obstructing somebody going about their normal daily routines then we would expect an intervention to be made according to what’s happening at the time.”