The implied probability of a June 23 British vote to remain in the European Union rose to 67 percent on Friday, according to Betfair odds.
The probability of a "remain" vote fell as low as 60 percent on Thursday before recovering to around 65 percent at the end of the day.
The numbers come after the suspension of campaigning for Britain’s European Union referendum after a lawmaker was fatally shot and stabbed.
The Thursday death of 41-year-old British Member of Parliament Jo Cox — in daylight on a street just as she arrived at a local library where she was due to hold a meeting with constituents — has sent shockwaves through Britain.
The last British lawmaker killed in an attack was Ian Gow, who died after a bomb planted by the Irish Republican Army exploded under his car at his home in southern England in 1990.
Reuters contributed to this report.