Prime Minister Boris Johnson faced a backlash from furious U.K. lawmakers on Thursday over his use of confrontational language in Parliament about opponents of his Brexit plan, as the Speaker of the House of Commons warned the country’s political culture has turned “toxic.”

U.K. Parliament reached boiling point on Wednesday when Johnson and his opponents engaged in hours of vitriolic debate over Brexit, with lawmakers hurling allegations of betrayal and abuse of power across the chamber.

Jo Cox, a 41-year-old lawmaker for the opposition Labour Party, was murdered on June 16, 2016, by Thomas Mair, a loner obsessed with Nazis and extreme right-wing ideology. She was the mother of two young children.

Cox’s husband Brendan said he was shocked by the vicious cycle of inflammatory language on display on both sides, saying both sides should ponder the impact of their language.

When asked how his late wife might have responded, Cox said: “She would have tried to take a generosity of spirit to it and thought about how in this moment you can step back from this growing inferno of rhetoric.”

“To descend into this bear pit of polarization is dangerous for our country,” he told the BBC. “It creates an atmosphere where violence and attacks are more likely.”

Brexit has illustrated a country divided about much more than the EU, and has fuelled soul-searching about everything from secession and immigration to capitalism, empire and what it means to be British.

The rage and ferocity of the Brexit debate has shocked allies of a country that has for over a century touted itself as a confident, and mostly tolerant, pillar of Western economic and political stability.

Cox was clear the language on both sides of the Brexit schism was troubling and the United Kingdom needed to come together rather than tear itself apart.

Some on both sides of the debate are now using the politics of contrived outrage to argue their point. Johnson says Parliament is betraying the will of the people over Brexit, while opponents cast him a dictator who has ridden roughshod over democracy to take the U.K. to the brink of ruin.

‘The culture was toxic’

Speaker John Bercow told lawmakers on Thursday to stop treating each other as enemies, saying the atmosphere in the House of Commons was the worst he had known in the 22 years since he was first elected.

“The culture was toxic,” Bercow said in Parliament. “May I just ask … colleagues please to lower the decibel level and to treat each other as opponents and not as enemies.”

House of Commons Speaker John Bercow urged moderation in Parliament and for lawmakers to ‘treat each other as opponents, not as enemies.’ (Parliament TV via Reuters)

Johnson taunted his rivals on his return to Parliament on Wednesday, goading them to either bring down the government or get out of the way to allow him to deliver Brexit.

Waving his arms and yelling “come on, come on,” Johnson implored his opponents in a raucous House of Commons session to bring a vote of no confidence in the government and trigger an election to finally break the Brexit impasse.

Opponents roared “resign,” and some cast him as a cheating dictator who should stand aside after the Supreme Court ruled unanimously that he had unlawfully suspended parliament.

In the June 23, 2016, referendum, 17.4 million voters, or 52 per cent, backed Brexit, while 16.1 million, or 48 per cent, backed staying in the bloc.

But after more than three years of political crisis since the referendum, it remains unclear when, if or on what terms the country will leave the bloc it joined in 1973.

Johnson refuses to apologize

In the uproarious debate in the House of Commons, Johnson refused to apologize for unlawfully suspending Parliament and instead attacked opponents for thwarting the will of the people over Brexit.

“We will not betray the people who sent us here; we will not. That is what the Opposition want to do,” Johnson said. “We will come out of the EU on 31 October.”

He provoked ire by repeatedly calling a law that forces him to ask the EU for a Brexit delay unless he can strike a deal as “the Surrender Bill.”

When opposition lawmaker Alison McGovern invoked the memory of Jo Cox and warned Johnson that the political culture was becoming toxic, he said the best way of honouring her memory was to “get Brexit done.”

After lawmaker Paula Sherriff told the House she had received death threats, some of which echoed the prime minister’s own rhetoric, Johnson replied: “I have never heard so much humbug in my life,” sparking uproar.

Nicholas Soames, the grandson of the U.K.’s World War II leader Winston Churchill, said he was appalled by the tone of the debate and it was the most poisonous atmosphere he can remember in 37 years in Parliament.

“I despair, to be frank,” said Soames, 71.

“I have grown up in a house where I believe the job of the prime minister even under very difficult circumstances is to try to bring the country together, and what the prime minister did yesterday was to drive it further apart.”

EU awaiting useful proposal 

European Union’s chief Brexit negotiator Michel Barnier on Thursday said the EU is still waiting for useful proposals to come from the U.K. to unblock stalled negotiations. (Vincent Kessler/Brexit)

As tensions ignite in Parliament​​​, the EU says it is still waiting for useful proposals to come from the U.K. to unblock stalled negotiations on Brexit.

EU Brexit negotiator Michel Barnier said Thursday he is “still ready to work on any new legal and operational proposal” from Johnson, but indicated insufficient progress had been achieved in the past few weeks.

Barnier said “we are still waiting,” underscoring the view that four papers over the past days fell far short to get real negotiations going again.

The EU already had a deal with the U.K. on departure terms but it was rejected in Parliament. Johnson now wants to drastically renegotiate the agreement or leave without a deal on Oct. 31.