Threats to MPs are at “unprecedented” levels, Metropolitan Police Commissioner Cressida Dick has said.
The Met chief disclosed that the number of crimes reported by MPs more than doubled in 2018 from 151 to 342 and was on course to rise further this year.
“Polarised opinion” on key issues was having a “big impact”, she told a parliamentary committee.
Ms Dick said women and people from ethnic minorities were being disproportionately targeted.
So far this year MPs and staff have already reported 152 crimes and over 600 incidents.
Appearing before the Joint Committee on Human Rights, Ms Dick said the murder of Labour MP Jo Cox in 2016 had contributed to an “extraordinary set of circumstances”.
Also giving evidence to the committee’s inquiry into democracy and free speech, Assistant Commissioner Neil Basu said Brexit was a “huge driver”.
He said crimes reported to police were “evenly split”, with 43% targeted against those in favour of leaving the EU and 47% aimed at people who want the UK to remain.
Ministers have said they intend to pass a law creating a specific new criminal offence of intimidating parliamentary candidates and party campaigners.
Under the proposals, anyone found guilty of harassing or abusing candidates or their officials during UK-wide elections would be liable to appropriate criminal penalties.