LONDON – It's not yet clear how the killing of a Labour Party lawmaker who campaigned for Britain to remain in the European Union will affect next week's referendum, but what is certain is that her death will be a turning point in what has been an often vitriolic battle over the country's future.
The referendum campaign was abruptly halted following the slaying of 41-year-old Jo Cox, who was shot and stabbed to death Thursday on the streets of her small-town constituency.
An idealistic politician who had praised the contribution of immigrants to Britain and championed the cause of war-scarred Syrian refugees, Cox had strongly favored the "remain" campaign. The 52-year-old man arrested for her killing has suspected ties to white supremacist, neo-Nazi groups.
"It's obviously a crisis moment, it changes things," Robert Worcester, founder of the Ipsos MORI polling firm said of the potential impact on Thursday's vote on whether Britain should remain in the EU or leave the 28-nation bloc.
"If one of them handles it badly, the backlash would be ferocious," he said. "Right now they are trying to figure out how to respond."
Worcester, a veteran pollster with decades of experience, said a tragedy like the killing of Cox just one week before a crucial vote is rare and could have unpredictable consequences on the public mood.
"I don't think the assassination itself will impact the vote, it's what they do with it," he said of the two sides in what has been a bitter and divisive campaign. "I think they will both express sadness, sadness that this would happen in this country, which is not a gun country, not a place where guns are carried."
The killing has silenced normally voluble analysts, academics and betting parlor managers who are reluctant to speculate on how the referendum vote may be impacted by the bloodshed.
Mark Dowding, a manager at BlueBay Asset Management, which oversees $58 billion in funds, said his company had taken a "short" position on the British pound — in effect betting it would go down, as is expected if Britain votes to leave the EU — but has changed course because of the assassination.
"I think this can have a significant impact on the vote," he said.
The rival camps have not yet said when the referendum campaign will resume. It had taken a decidedly nasty turn in the days before the shooting as the "leave" side hammered home what it maintains are the risks of higher rates of immigration into Britain.
Days before the shooting, the leader of the anti-EU UK Independence Party, Nigel Farage, unveiled a poster showing hordes of dark-skinned immigrants entering Europe on foot, suggesting that only by leaving the EU would Britain be spared this onslaught.
The words "BREAKING POINT" in capital letters were emblazoned atop the image.
"This is scaremongering in its most extreme and vile form," said Dave Prentis, the leader of UNISON, one of the UK's largest trade unions, which backs remaining in the EU.
In the days before the shooting it appeared the "leave" campaign's focus on immigration might be paying dividends as Britain's legal bookmakers changed their odds to reflect an increasing chance that voters would choose to leave the EU.
But with the slaying of Cox, who had sought more help for Syrian refugees victimized by the civil war, some commentators are now contending such divisive "leave" campaign tactics helped create a climate in which a British lawmaker was killed for the first time in a quarter century.
"Nigel Farage isn't responsible for Jo Cox's murder," commentator Alex Massie wrote in The Spectator of the anti-EU party leader.
"Nor is the Leave campaign. But they are responsible for the manner in which they have pressed their argument. They weren't to know something like this was going to happen, of course, and they will be just as shocked and horrified by it as anyone else. But, still. Look. When you encourage rage you cannot then feign surprise when people become enraged."
The 'leave' campaign is likely to tone down its anti-immigrant rhetoric, and perhaps take a more conciliatory approach when campaigning resumes.
The motive for the killing is not yet clear, but the suspect, identified locally as Thomas Mair, has been linked to white supremacist groups opposed to immigration. Some witnesses said he shouted "Britain first!" during the frenzied attack.
In a country where gun violence is extremely rare, the spectacle of a serving member of Parliament being slain after meeting with constituents seems to have made Britons take a collective, fearful deep breath.
"It really has had a huge effect on the whole country," said Mark Boleat, policy chairman at the City of London Corporation. "I think more than people could have imagined... I think it's made everyone pause and think."
Associated Press writer Leonora Beck in London contributed to this report.