The number of threatening letters sent to MPs has risen significantly since the 2016 EU referendum.
New figures released by the Metropolitan Police under the Freedom of Information Act shows a jump in letters with intent to cause distress reported to the police rose from 39 in 2016 to 101 in 2018.
The number of crimes reported on the parliamentary estate was recorded as 236 crimes in 2018 – up 32% from 2017 and a 45% increase on 2016.
The police also said it had received reports of harrassment last year, four in 2017 and three in 2016.
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 blamed Brexit for the spike in abuse that MPs are facing, and said politicians’ views on the debate was the issue.
“I’m sure this high spike is linked with the Brexit issue which has been very toxic,” she told Sky News.
“I mean our postbags and emails… we’re constantly being told, you’re not following the will of the people, you’re being traitors.”
Qureshi read out an email sent to her just the day before, which read “you deserve all the abuse you get”.
She said: “There has been a group of people who already thought it was acceptable, then after the referendum they felt emboldened and like it was respectable to send this abuse.”