MPs have faced a significant rise in the number of threatening letters sent received since 2016 amid fears they have been targeted because of their beliefs on Brexit .
Figures released by the Metropolitan Police under the Freedom of Information Act show a jump in letters being sent with the intent to cause distress, from 39 in 2016, to 101 in 2018.
It came as it emerged that Speaker John Bercow is drawing up plans to have CCTV cameras installed inside MPs offices to help to reduce the level of sexual harassment and bullying.
Overall, 236 crimes were reported on the parliamentary estate in 2018, up 32% from 2017 and a 45% increase from 2016, when there were 163 reports.
The Met said it received four reports of harassment in 2018, four in 2017 and three in 2016.
It follows allegations of sexual harassment and bullying which hit Westminster in 2017.
Other offences reported in 2018 include cocaine possession, cannabis possession and common assault.
In 2016 there was one report of false imprisonment, followed by one of stalking in 2017.
There was one report of murder following the death of PC Keith Palmer who was killed in the 2017 Westminster terror attack.
Labour’s shadow police minister Louise Haigh said: “It’s no surprise that the scale of threats has ramped up over the last few years as political debate has become increasingly toxic and violent.
“The language of treachery and betrayal has been normalised by some with significant political platforms and it has created a genuinely dangerous environment.”
Labour MP Yasmin Qureshi, a victim of online harassment by a man who was later jailed, told Sky News that the level of abuse had worsened since the Brexit vote three years ago.
“I’m sure this high spike is linked with the Brexit issue which has been very toxic,” she said.
“I mean our postbags and emails… we’re constantly being told, you’re not following the will of the people, you’re being traitors.”
The Speaker’s office said that Mr Bercow is preparing to take “serious” action ahead of the publication of the damning report into the ‘Pestminster’ scandal of 2017 which saw dozens of abuse allegation made against politicians.
An inquiry by Gemma White QC is expected to be highly critical of the conduct of some MPs when it is published in the next fortnight.
And an independent inquiry into MPs behaviour by Dame Laura Cox, which excluded incidents reported by their own staff, found widespread bullying and harassment behaviour.
A third investigation by Naomi Ellenbogen into misconduct in the House Of Lords will be released soon.
Proposals being considered by Mr Bercow could see researchers issued with GPS-tracked alarms to record the exact time and location of any alleged assault.
Sales of alcohol could also be banned on the Parliamentary estate before 6pm.