Tensions over Brexit, and warnings of a backlash from nationalists if it does not happen soon, have rekindled fears of political violence in Britain. The threat seemed acute on Wednesday, as video of British soldiers using a photograph of opposition leader Jeremy Corbyn for target practice appeared on Snapchat, and the trial of a neo-Nazi who planned to assassinate a pro-European member of Parliament ended.

Corbyn said that he was “shocked” by the video, which was shared on Twitter by current and former members of the British armed forces, after he emerged from talks with Prime Minister Theresa May aimed at finding a way to allow the stalled British exit from the European Union to proceed.

In the House of Commons, Rosie Cooper, a member of Parliament for Corbyn’s Labour party, described a neo-Nazi plot to kill her as part of a trend in which MPs have been subjected to threats based on their views about Brexit. “I was to be murdered to send a message to the state, to send a message to this place,” Cooper said. “Members of this House are regularly abused and attacked. Our freedoms, our way of life, our democracy is under threat.”

Jack Renshaw, the young neo-Nazi who confessed to plotting Cooper’s murder, was a member of a banned group that had celebrated the assassination of Jo Cox, another pro-European Labour MP, just before the 2016 referendum on the United Kingdom’s membership in the European Union.

The end of Renshaw’s trial permitted the activist group Hope Not Hate to reveal its role in exposing the plot, through the undercover work of a former member of the banned group.

Cooper, who voted for the U.K. to remain in the EU in the 2016 referendum but represents a region that voted to leave, was one of the few Labour MPs to support May’s Brexit deal when it was rejected by Parliament last week. “My position on Brexit has been consistent and remains unchanged,” she explained. “Quite simply the will of the people and the outcome of the referendum should be respected. In West Lancashire a majority of people, 55% voted to Leave the EU.”

After she supported the Brexit deal in Parliament, Cooper’s name was added to a list of “Brexit Quislings” by a pro-European Twitter activist.

A spokesperson for the British defense ministry told Sky News that the video of the soldiers firing at Corbyn’s image, which was recorded at a base in Afghanistan, “shows totally unacceptable behavior” and “a full investigation” into the actions of the paratroopers would be conducted.

Concerns about the apparent spread of far-right politics inside the military previously surfaced in October, when a group of soldiers was filmed cheering for Tommy Robinson, the anti-Muslim founder of the English Defence League.

Robinson, who is now an adviser to the pro-Brexit party UKIP, addressed an angry “Brexit Betrayal” protest outside Parliament last week, in which MPs were denounced as “traitors” and the threat of violence was never far below the surface.

Robinson was invited to join UKIP by the party’s new leader, Gerard Batten, who said last week that Brexit had been delayed through “the connivance of the traitors, quislings, and collaborators in the British parliament.”

Corbyn is reportedly viewed with extreme skepticism by some senior members of the British armed forces, due to his long record of opposition to its nuclear weapons and his support for dissidents in Northern Ireland, including former members of the Irish Republican Army.

The video of paratroopers firing at Corbyn’s photo was roundly condemned by members of his party, who called it incitement, and by the defense minister.

Owen Jones, a Guardian columnist, wrote that the clip was “absolutely horrific, and speaks of a growing dangerous radicalisation on the right against Corbyn in particular and the left in general.”

“The Tory Party and much of the British media portray Jeremy Corbyn and the left in general as terrorist-supporting Britain-haters,” Jones added. “This video is one of the consequences.”

Pro-Brexit Conservative MPs, outraged by the prime minister’s decision to look for compromise with Corbyn, continued to denounce him in such terms even after the video emerged on Wednesday. Iain Duncan Smith, a former Conservative leader, told the BBC that Corbyn’s “sole purpose in life is to do real damage to the country.”

In a letter resigning from May’s cabinet over her talks with Corbyn, another Conservative MP, Nigel Adams, denounced the prime minister for seeking a deal “cooked up with a Marxist who has never once in his political life put Britain’s interests first.”

Tracy Brabin, the Labour MP who now holds Jo Cox’s seat, condemned Priti Patel, a former minister in May’s cabinet, for even more extreme comments about Corbyn.

As Brabin noted, Darren Osborne, a white supremacist terrorist who drove into a crowd of Muslims outside a mosque in London in 2017, killing one man, said in court that he had hoped to kill Corbyn, figuring “it would be one less terrorist [on] our streets.”

Osborne’s partner later testified that he had been “brainwashed” by obsessively watching Tommy Robinson videos online.

“I think we are in an incredibly febrile atmosphere,” Martin Hewitt, chair of the National Police Chiefs’ Council, told reporters. “I think there is a responsibility on those individuals that have a platform, and have a voice, to communicate in a way that is temperate and is not in any way going to inflame people’s views or cause any actions out of there.”

The video of the soldiers pretending to assassinate Corbyn was, predictably, defended by a trans-Atlantic alliance of far-right trolls. James Delingpole, a Breitbart columnist, asked, “How is it wrong for the Army to train against terrorist-supporting, Jew-hating, Commie revolutionaries?” Jonathan Schanzer, a vice president of the Foundation for Defense of Democracies, a neoconservative think tank, wrote that it was “reassuring that British soldiers find him repugnant.” (Accusations that Labour has been slow to discipline or expel party members for making anti-Semitic remarks have been distorted by Corbyn’s political enemies into supposed proof that his criticism of Israeli rights abuses is motivated by anti-Semitism.)

One of the the former soldiers who approvingly shared the clip on Twitter, an Iraq war veteran from Belfast named Trevor Coult, dismissed it as “a bit of tomfoolery.” (A screenshot of a tweet Coult later deleted shows that the copy of the video he shared was uploaded to Twitter by a petty officer who is currently serving in the Royal Navy.)

Last month, Coult suggested that British Army veterans were showing restraint by not killing Corbyn for his prior criticism of myth-making around the British role in World War I.

Coult, a former sergeant, also tried to defend the soldiers, who were all members of the Parachute Regiment, by claiming that their hatred for the left-wing leader was to be “expected when you consider that Corbyn supports the very men who thrived on killing Paratroopers!” Coult was referring to Corbyn’s support for former IRA members who fought with soldiers from the British Parachute Regiment in Northern Ireland.

The Parachute Regiment is notorious in Ulster for carrying out the Bloody Sunday massacre in 1972, killing 13 unarmed civil rights marchers in the city of Derry. Last month, prosecutors in Northern Ireland reopened that case and decided to charge one of the former paratroopers with two counts of murder and four of attempted murder.

Coult, whose father was deployed to Northern Ireland as a soldier in 1969, has been an outspoken critic of the prosecution of the former paratrooper, known only as Soldier F.

The primary stumbling block over Brexit has been concern that it could reignite violence in Northern Ireland by effectively repartitioning Ireland with customs and immigration checks along the British-imposed border that divides the island in two.

Coult has also campaigned for a new fringe political party that recently threatened to “delete” every member of the British Parliament.