There could be a "creeping rise" in people radicalised by far-right extremism as a result of Brexit's divisive potential, the head of the Metropolitan Police's counter-terrorism operations has warned.
Assistant Commissioner Neil Basu said the rise of divisions amid Brexit could allow a way in for far-right extremist ideology in the UK.
"What's most concerning me about Brexit is its potential to divide communities and set communities against each other," Mr Basu told BBC Radio 4's Today programme on Wednesday.
"What we saw after the referendum was a rise in hate crime, and a rise in far-right rhetoric, and we have seen the growth of organisations like National Action."
While the threat of far-right extremism is still relatively small when compared to those posed by al-Qaida in the past and by ISIS over the past few years, the head of the Met Police counter-terrorism operations remarked it is still important to combat it.
"What I'm concerned about is the creeping rise of that [far-right extremism], and if we aren't clear that we are combating that threat then that's my concern."
Earlier this month Scotland Yard was forced to increase its presence in the political heart of London after Tory MP Anna Soubry was branded a Nazi by a mob during television interviews and was then followed to the Palace of Westminster.
Other incidents of radicalisation include abuse received by Labour MP for Great Grimsby, Melanie Onn. Onn tweeted some of the abuse she has received, calling her a "traitor" and warning her to "watch your back as you will not be forgiven".
As March 29, 2019 - the day the UK is expected to leave the EU - approaches and the government is still discussing Brexit deals with Brussels, the prospect of leaving without a deal has not been ruled out.
Leaving the European Union without a deal, Mr Basu said on the Today programme, would put the country in a "very bad place."
"To leave without [...] being able to exchange data or biometrics on people who might be criminals or terrorists would be a very bad place for this country, and for Europe, to be."
Mr Basu spoke at the launch of a major cinema advert campaign to increase awareness of suspicious activity and encourage people to report it to police.
The 60-second film shows a series of scenarios, such as a man stockpiling hazardous material and another buying weapons, before rewinding and zooming in on the danger.
In 2017 and 2018, around a fifth of the information passed to police from the public had a "significant" role in thwarting attacks, he said.
Four far-right extremist plots and 14 Islamist terror plots were foiled in the last two years.