Campaigning for Britain's vote on EU membership resumed on Sunday after a three-day hiatus prompted by the killing of a pro-EU lawmaker, but pledges of a more respectful tone were quickly tested by a fresh row over immigration.
Three opinion polls ahead of Thursday's vote showed the 'Remain' camp recovering some momentum, although the overall picture remained one of an evenly split electorate.
The killing of Jo Cox, a 41-year-old mother of two young children, shocked Britain, raised questions about the tone of campaigning and could yet prove a defining moment in what is Britain's biggest political decision for decades.
Both sides sought to adopt a more measured style on Sunday, paying their respects to Cox but sticking closely to the immigration-versus-economy debate that has defined the campaign.
"I hope, because of the tragic death of Jo, we can have a less divisive political debate in our country," Finance Minister George Osborne, a leading conservative 'Remain' campaigner, told ITV's "Peston on Sunday" show.
"Particularly in the last few days of this referendum we’re going to have less baseless assertion and inflammatory rhetoric and more reasoned argument and facts," he said.
Cox, a Labour Party lawmaker and ardent supporter of EU membership, was shot and stabbed in the street in her electoral district in northern England on Thursday. A 52-year-old man appeared in a London magistrate's court on Saturday, charged with her murder.
But the heated nature of the debate, which has so far seen 'In' campaigners accused of scaremongering on the economy and the 'Out' campaign's immigration focus criticized as divisive, soon resurfaced after the temporary truce.
Osborne criticized as "disgusting and vile" a poster unveiled by 'Leave' campaigners last week showing a line of refugees under the slogan "Breaking Point", saying it was reminiscent of literature used in the 1930s.
Prime Minister David Cameron said the poster was an attempt to scare voters and a senior member of his party, Sayeeda Warsi, said it had put her off voting for 'Out'. She will now vote for 'In'.
"Are we prepared to tell lies, to spread hate and xenophobia just to win a campaign? For me that's a step too far," she told the Times newspaper.
UK Independence Party (UKIP) leader Nigel Farage, who was pictured in front of the poster, said the EU had failed to control immigration properly and had compromised safety in Europe by allowing in religious extremists who wanted to attack Western states.
"Something that is true can't be a scare, can it?" Farage told BBC radio when asked about the poster. "It was a comment about us being part of a European Union that is failing."
The official 'Vote Leave' campaign sought to distance itself from the poster but defended its focus on immigration - an issue that has resonated with many voters.