Opposition Labour leader Jeremy Corbyn called for "kinder politics" in Britain on Monday, urging politicians to drop the "hatred and division" seen in some of the campaigning ahead of Thursday's EU referendum.
"We must come together to change our politics," Corbyn told parliament in a special session to pay tribute to murdered Labour lawmaker Jo Cox.
"We need a kinder and gentler politics," he said. "We all have a responsibility not to whip up hatred and division."
Corbyn said Cox had used her first speech in parliament in June 2015 to support the positive impact of immigration in Britain.
"In her tragic death we can come together to change our politics, to tolerate a little more and condemn a little less," he said.
Prime Minister David Cameron praised Cox's "passion and spirit" and said she "epitomised the best of humanity" through her efforts to help refugees and people in some of the world's poorest communities.
Andrew Mitchell, a lawmaker from Cameron's Conservative Party, said Cox would have wanted British politicians to "redouble our efforts to resolve the greatest catastrophe of age," the conflict in Syria.
Cox's death last week has prompted many calls for the Leave and Remain campaigns to drop their use of vitriol as they try to make their points in the debate on a British EU exit, or Brexit.
Friends and supporters of Cox have organized a large "rest in power" event on Wednesday in London's Trafalgar Square, along with smaller events in other cities to mark what would have been her 42nd birthday.
An online appeal to fund charities supported by Cox had raised nearly 900,000 pounds (1.3 million dollars) in three days by Monday.
Senior Conservative politician Sayeeda Warsi on Monday dropped her support for the Leave campaign ahead of Thursday's referendum, saying she wanted to reject "the politics of hate."
"Toxic, divisive and xenophobic political campaigning should have no place in a liberal democracy. The politics of hate should always fail," Warsi, a member of the upper house of parliament, said on Twitter.
There has been "a shift in campaigning, a core vote strategy, the end of inclusive politics," she wrote above a photograph of Vote Leave co-leader Boris Johnson and a link to a report on the group's recent focus on immigration.
Cameron welcomed support for Remain from British industry on Monday, including statements from: Virgin founder Richard Branson; the Ford motor company; a car industry body; and the Premier League, which represents England's top 20 football clubs.
UK Independence Party leader Nigel Farage on Monday defended a Brexit poster he had unveiled on Thursday showing a crowd of migrants queuing to enter Britain, under the headline "Breaking point."
Farage was widely criticised for the poster, with Warsi telling The Times that it was the "step too far" that ended her support for Leave.
Leave supporters have accused Cameron of using Cox's death to bolster his campaign for Remain votes in the referendum.
After Cox's death on Thursday, police charged 52-year-old local man Tommy Mair with her murder. Mair had a history of mental illness and had supported racist and right-wing extermist groups, according to media reports.