LONDON — Lawmakers quitting in fear of violence, claims of endemic racism infecting the major parties, and a prime minister directing populist vitriol against his colleagues.

Britain is now headed for its first December nationwide elections in almost 100 years. But instead of bringing yuletide cheer, the contest is shaping up to be a toxic brawl centered around Brexit.

"This has the potential to be the angriest election we have had in Britain for a long time," said Sunder Katwala, director of British Future, a think tank that focuses on issues of identity. "Britain is discovering that it is a more divided country than it ever realized."

The Dec. 12 poll is being billed as an extraordinary vote, one in which the winner will not only govern for a few years but could also hold the power to set Britain's geopolitical course for decades to come.

If Prime Minister Boris Johnson can achieve a convincing victory, as polls suggest he might, he would have the power to drive through his hard-line Brexit plan.

But if the opposition Labour Party and others can at least stop him from gaining a majority, they might be able to alter Brexit or cancel it altogether.

Indeed, there is every possibility that the public might elect a Parliament just as deadlocked as this one.

Brexit has sparked the country's biggest crisis since World War II, as politicians have struggled to translate the 2016 referendum to leave the European Union into reality.

It has created bitter divisions, upended centuries-old norms, and contributed a hostile atmosphere that has already set the tone for this upcoming election.

Daily protests outside Parliament have descended into abuse yelled at legislators, some of whom have required police escorts in and out of the building.

Senior Conservative Jacob Rees-Mogg, whose upper class persona and stalwart Brexiteer credentials have become a lightning rod for critics, was guarded by officers as he walked home with his 12-year-old son.

Police officers escort Britain's Leader of the House of Commons Jacob Rees-Mogg as he leaves Parliament. Tolga Akmen / AFP - Getty Images

Diane Abbott, the U.K.'s first black female member of Parliament, also required a police escort outside the building.

The abuse is online, too, with lawmakers suffering a deluge of death and rape threats — with Abbott receiving more abuse on social media than any of her colleagues, according to Amnesty International. Most of the victims are women, although men are not immune.

"The tone is going to be very unpleasant. It's going to be very nasty particularly on social media," said Anand Menon, director of the U.K. in a Changing Europe think tank.

For some, this violent intimidation has become so distressing that they are walking away from their careers.

Liberal Democrat Heidi Allen announced Tuesday that she would be standing down at the election because of the sheer level of this "dehumanizing" abuse.

"I am exhausted by the invasion into my privacy and the nastiness and intimidation that has become commonplace," she wrote in an open letter to her constituents.

"Nobody in any job should have to put up with threats, aggressive emails, being shouted at in the street, sworn at on social media, nor have to install panic alarms at home," she said.

Boris Johnson addresses the House of Commons on Tuesday. Jessica Taylor / AFP - Getty Images

Lawmakers do not need to imagine what happens when these threats become reality. In June 2016, days before the Brexit referendum, Labour lawmaker Jo Cox was murdered in the street by a Nazi-supporting terrorist. He shouted "Britain first" during the killing and called Cox a "traitor" at trial.

In October 2017, police busted a neo-Nazi group planning to murder another Labour lawmaker, Rosie Cooper.

Boris Johnson has been widely accused of stoking the hostility rather than seeking to calm the situation. Since July when his party selected him to be their leader and thus the country's prime minister, he has sought to cast Parliament as a cabal of undemocratic elites, plotting to steal away the public's Brexit vote.

This people-versus-Parliament strategy has seen Johnson use language such as "betrayal" and "surrender."

This week I received an anonymous letter to my constituency office here is what it said. @10DowningStreet might think we are "humbugs" about his words but they are literally being used in death threats against me. pic.twitter.com/au6E0v9CpI — Jess Phillips Esq., M.P. (@jessphillips) September 25, 2019

An investigation by the Financial Times found following one particularly angry parliamentary debate in September, the level of online vitriol directed at elected officials rose sharply.

But it's not only Brexit causing rancor in the corridors of power.

Jeremy Corbyn's Labour Party has been locked in an anti-Semitism crisis that has seen a number of lawmakers resign, coinciding with the party's steady decline in the polls.

Jeremy Corbyn gave the green light for the early general election Tuesday. Jessica Taylor / Reuters

Corbyn himself has been accused of being slow or failing to expel candidates accused of anti-Semitism, and the leader has shared platforms with people with alleged anti-Semitic views.

The latest to quit was Louise Ellman, a Labour lawmaker for 55 years, who said in her departing letter earlier this month that Corbyn was "not fit to serve as our prime minister."

Under Corbyn's leadership, she alleged, "anti-Semitism has become mainstream in the Labour Party."

"Jewish members have been bullied, abused and driven out," she added. "Anti-Semites have felt comfortable and vile conspiracy theories have been propagated."

Then there's the Brexit Party led by President Donald Trump's friend Nigel Farage, who has been widely accused of racist and xenophobic language in the past.

It remains to be seen what role this newcomer group will play in December's vote.