The British pound tumbled on currency markets Monday – and Prime Minister David Cameron was forced into an improbable mid-campaign alliance with three left-of-centre parties – after a series of opinion polls suggested those in favour of pulling Britain out of the European Union had seized the lead three weeks before a crucial referendum.
The pound's fall highlighted growing worries that a victory for the Vote Leave camp – once considered a long shot – is an increasingly possible outcome of the June 23 plebiscite, in which voters will be asked whether they want to Remain a member of or Leave the EU. Politicians and economists have repeatedly cautioned that a Leave vote could have unpredictable consequences for both the Britain and the wider European economy.
Despite such warnings, three new large-scale opinion polls by different companies published Sunday and Monday showed the Vote Leave side with a lead of between three and five percentage points, pushing it beyond the margin of error for the first time in this closely fought campaign.
John Curtice, Britain's top polling guru, told The Globe and Mail that the three polls might be the first real sign of a shift in the campaign, which has otherwise been effectively deadlocked since the start of the year. He noted that while Internet polls had shown an effective 50-50 split throughout, telephone polls still put the Remain side comfortably ahead.
(British pollsters took a drubbing after last year's general election where none predicted the eventual outcome, which saw Mr. Cameron's Conservatives win a majority in the House of Commons.)
All three of the most recent surveys were conducted online, and all three suggested that a large number of voters – 11 per cent in one poll, 14 per cent in another – had yet to make up their minds as to how they would vote in a referendum that could dramatically redefine Britain's political and economic relationship with both Europe and the rest of the world.
The latest results jolted markets that had settled into a complacent expectation that the Remain side would eventually prevail. The pound fell 0.9 per cent versus the U.S. dollar, to $1.44, and 0.5 per cent against the euro, to €1.27.
The apparent surge in support for a so-called "Brexit" from the EU – with a growing number of Britons seemingly swayed by the argument that their country needs to quit the EU in order to take back control of its borders and immigration policy – also injected a fresh sense of urgency into the rival campaigns.
Mr. Cameron – who leads the Remain campaign – launched a new cross-party effort on Monday, speaking alongside senior politicians from the opposition Labour, Green and Liberal Democrat parties at a rally in London, an alliance that was slammed as "desperate" by Matthew Elliott, chief executive of the Vote Leave campaign committee.
Mr. Cameron, who has seen his own cabinet and caucus splinter over the EU debate, accused pro-"Brexit" politicians of dabbling in "fantasy politics" while avoiding laying out a specific vision of how Britain could thrive outside the EU.
Mr. Cameron said voting to quit the 28-country bloc would put "a bomb under our economy. And the worst thing is we'd have lit the fuse ourselves."
Boris Johnson, the Conservative cabinet minister who co-leads the Vote Leave campaign – and clearly covets Mr. Cameron's job – retorted during a campaign stop in Stratford-upon-Avon that the Remain side was resorting to telling "scare" stories of what would happen to Britain's economy in the event of a Brexit. He claimed Britain would have to further compromise its sovereignty and pay billions more to help Brussels bail out failing economies such as Greece's if it remained inside the EU.
"I think it is a delusion to think we can somehow gain greater prosperity by bartering away our freedom and democracy," Mr. Johnson said.
An ICM poll, conducted June 3-5 and published on Monday, put Leave ahead with 48-per-cent support to 43 per cent for the Remain camp. A larger YouGov/ITV poll, conducted June 1-3, showed the Leave side at 45 per cent, up five points from a month earlier, versus 41 per cent for Remain. Those results followed a poll published Sunday by Opinium Research that put Leave at 43 per cent and Remain at 40 per cent.
The results of the three latest polls pushed the Leave side into a 51-per-cent to 49-per-cent lead in a poll of polls conducted by Mr. Curtice's UK in a Changing Europe initiative, which takes into account the work of six different polling firms.
Mr. Johnson, the former mayor of London, appeared in a buoyant mood on Monday, perhaps energized by a fourth poll, which found that a whopping 69 per cent of the subscribers to The Daily Telegraph newspaper were now planning to vote Leave. The same poll found 42 per cent – by far the biggest share – named Mr. Johnson as their preference to succeed Mr. Cameron as Conservative leader.
Since Telegraph readers lean heavily Conservative, the poll results highlighted the Remain side's – and thus Mr. Cameron's – reliance on left-wing voters who traditionally support the Labour Party, which is pro-EU, and the separatist Scottish National Party.
However, Labour leader Jeremy Corbyn has been accused of offering only lukewarm support to the Remain side. He did not campaign alongside Mr. Cameron on Monday, although Labour's former deputy leader Harriet Harman did take the stage alongside the Prime Minister.
Meanwhile, many suspect the SNP would be happy to see the Leave side win, since a result that sees Britain vote to leave the EU – against the wishes of a majority of Scots – could create the conditions for another referendum on Scotland's independence.