By Michael Holden and Kylie MacLellan
LONDON (Reuters) - MP Jo Cox, who was shot and stabbed a week before Britain's referendum on European Union membership, died because of her political views and had been deeply troubled by the tone of the campaign, her husband said on Tuesday.
Prime Minister David Cameron appealed to voters across the generation gap to back staying in the EU, two days before a closely fought referendum that will shape the future of Europe. The campaign to leave the EU has echoes of populist movements across Europe and in the United States.
The murder of Cox, a 41-year-old mother of two young children who was an ardent supporter of EU membership, shocked the country and abruptly changed the tone of a caustic campaign that has polarised Britons.
"She had very strong political views and I believe she was killed because of those views," her husband Brendan Cox told broadcasters. "She died because of them and she would want to stand up for those in death as much as she did in life."
It was unclear how Brendan Cox's words might influence voters.
Cox had been worried about Britain's political culture, including a coarsening of language and people taking more extreme positions, he said. She was also concerned about divisive politics globally.
"She worried about the tone of the debate" that focused increasingly on immigration and "about the tone of whipping up fears and whipping up hatred".
"I think the EU referendum has created a heightened environment for it but actually it also pre-existed that. It's something that's happened over the last few years I think and again not just in the UK but globally," Brendan Cox said.
Britons vote on Thursday on whether to quit the 28-nation bloc amid warnings from world leaders, investors and companies that a decision to leave would diminish Britain's influence and unleash turmoil on markets.
"BRITS DON'T QUIT"
In an address outside his Downing Street office, Cameron hammered home his message that leaving the EU would jeopardise Britain's economy and its national security, with fewer jobs, fewer allies and higher prices.
"Brits don't quit," he said, using the official backdrop to make a direct pitch to older voters considered more eurosceptic and more likely to vote.
"It will just be you in that polling booth. Just you, taking a decision that will affect your future, your children's future, your grandchildren's future."
The Conservative prime minister's remarks came as an opinion poll showed very narrow support for staying in the EU. The Survation poll put the "Remain" camp just one percentage point ahead of the campaign for a so-called Brexit, well within the margin of error.
Opponents said Cameron's appearance suggested he was worried about the outcome.
As each side sought to play its last trump cards, the pro-EU "Britain Stronger in Europe" campaign issued a final poster of a door leading into a dark void with the slogan: "Leave and there's no going back."
If Britain votes to leave, Cameron would face pressure to resign, though he has said he will continue as leader.
'POLITICAL KILLING'
Campaigning was suspended for three days after Cox's killing in northern England last Thursday.
Some Leave campaigners accuse the Remain camp of exploiting her death.
Cox's widower spoke of the grief of their two young children though he said that public support for the family had been of some consolation.
"It also helps the children see that what they're feeling and other people are feeling, that the grief that they feel isn't abnormal," he said.
After Cox's killing, opinion polls indicated sentiment had swung back to the Remain side after a shift towards Leave.
An earlier ORB survey for the Daily Telegraph put support for Remain at 53 percent, up 5 percentage points on the previous one, with Leave on 46 percent, down three points.
"All the signs of ORB's latest and final poll point to a referendum that will truly come down to the wire," said Lynton Crosby, a political strategist who advised the Conservatives at the last national election in 2015.
Former England soccer captain David Beckham, a popular public figure, added his voice to Remain's list of celebrity supporters. "For our children and their children we should be facing the problems of the world together and not alone," he said.
Leave campaigners stepped up their focus on what they call uncontrolled immigration, saying Cameron had been warned four years ago his goal of reducing net arrivals was impossible due to EU rules.
The anti-EU UK Independence Party issued a poster showing a traffic jam with the message "The school over-run" and saying nearly one in four of Britain's primary schools were full or oversubscribed.
The Leave camp says it is the anti-establishment choice, and its message that EU membership has handed political control to Brussels and fuelled mass immigration has struck a chord with many Britons.
Already shaken by differences over migration and the future of the euro zone, the EU would lose its second-largest economy, one of its top two military powers and by far its richest financial centre.