By Michael Holden
LONDON (Reuters) - Opinion polls on Tuesday suggested growing support amongst Britons for staying in the European Union but the vote in two days time which will have far-reaching consequences for Britain and Europe remains on a knife edge.
Britons will vote on Thursday on whether to quit the 28-nation bloc amid warnings from politicians, economists and trade bodies across the globe that a decision to leave would plunge Britain and possibly much of Europe into recession.
The bloc - already shaken by differences over migration and the future of the euro zone - would lose its second-largest economy, one of its top two military powers and by far its richest financial center.
George Soros, the billionaire who bet against the pound in 1992, wrote in an article for Britain's Guardian newspaper on Tuesday that a vote to leave would trigger a bigger, more disruptive devaluation in Britain's currency than the fall on Black Wednesday.
Opinion polls published since the murder of pro-EU lawmaker Jo Cox, who was shot and stabbed to death in her constituency in northern England last Thursday, have suggested sentiment might be moving towards an "In" vote.
An ORB poll for Tuesday's The Daily Telegraph newspaper found support for Remain at 53 percent, up 5 percentage points on the previous one, with support for 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 ruling Conservative Party at the last national election in 2015.
The "Leave" camp had "failed to quash the almost ubiquitous perception that it is the riskier of the two options," he said.
Social research body NatCen also published a survey that found Remain on 53 percent and Leave on 47 percent, using a method that took on recommendations by an official inquiry into why pollsters got last year's election wrong, although its research was conducted from May 16 to June 12.
However, an online poll by YouGov for The Times showed Leave ahead on 44 percent, up one point, with Remain on 42 percent, down two points. That survey was conducted over the weekend after Cox was killed.
Campaigning was suspended for three days after the killing, which led to soul searching about the campaign and its tone, with Jeremy Corbyn, leader of Cox's opposition Labour Party, saying her murder was likely "extreme political violence".
Some "Leave" campaigners accuse the "Remain" camp of exploiting the murder as part of what they portray as a campaign of scaremongering over the referendum by the establishment at home and abroad.
Turnout is predicted to be key to the result, and the ORB poll found that Remain supporters, who had been regarded as being more apathetic, were becoming increasingly motivated to vote as polling day approaches.
STERLING AND SHARES BOOST
Prior to the murder of Cox, polls had shifted towards "Leave", and the indication that an "In" vote was now more likely has boosted sterling and shares. Britain's FTSE-100 shares index jumped 3 percent on Monday while in early trading on Tuesday, the British pound was at a three-week high against the dollar.
According to Betfair betting odds, the implied probability of a British vote to remain in the European Union was 75 percent.
The "Out" campaign argues that it is the anti-establishment choice, and its message that EU membership has handed political control to Brussels and led to uncontrolled immigration appears to have struck a chord with many Britons.
That issue again gained prominence on Tuesday when Prime Minister David Cameron's former close aide Steve Hilton said the prime minister had been told four years ago that his target to reduce net immigration to Britain to the tens of thousands was impossible.
"We were told, directly and explicitly, that it was impossible for the government to meet its immigration target as long as we remained members of the EU, which of course insists on the free movement of people within in," Hilton, who has already said he backs Brexit, wrote in the Daily Mail newspaper.
Those wishing to stay in the bloc, including Cameron, have focused on what they describe as the economic advantages provided by EU membership and the risks posed by leaving.
The pro-EU camp, including former prime ministers Tony Blair and John Major, have warned that an exit could also trigger the break-up of the United Kingdom by prompting another Scottish independence vote if England pulled Scotland out of the EU.
The Remain camp not only boasts the support from the majority of senior business figures and world leaders such as U.S. President Barack Obama and Angela Merkel, but also well-known stars from stage, screen and sport.
On Tuesday, former England soccer captain and hugely-popular David Beckham added his voice to that list. "For our children and their children we should be facing the problems of the world together and not alone," he said.
(Additional reporting by Elisabeth O'Leary and Estelle Shirbon; Editing by Guy Faulconbridge)