The latest set of polls judging the outcome of Britain's European Union referendum on June 23 converge on one finding: the vote is too close to call.
Recovering ground in the past two weeks, Leave is now within two points at 51-49 on the Daily Telegraph's monitor of those who have made their decision.
The Mirror had the same 51-49 split on Monday. However, when it included undecided voters, Leave took a lead --- only its second of the campaign --- at 45-42.T
he Financial Times still has Remain in front at 45-43, with 12% undecided.
The bookmaker Paddy Power has raised the odds of a Remain victory to 2-5, or about a 71% chance, from last week's 1-3. Leave is 2-1 to triumph.
The uncertainty is affecting the value of the pound, showing the highest level of volatility since the financial crisis of 2008-2009. The pound dropped about 1.5 cents to $1.44 on Monday, following a decline of 2 cents last week.
The latest polls reinforce our analysis last week of a race in which turnout will be essential. We think the youth vote in particular could be decisive.
They also indicate that victory may not be determined by core issues. Despite every forecast predicting damage to the British economy with departure from the EU, the likelihood --- possibly because of the complexity of economic and financial matters, possibly because of Leave's success in diverting attention --- is that this alone will not ensure a vote for Remain. Conversely, the Leave campaign's dire predictions of Britain overrun by immigrants, while succeeding in keeping economics off the top of the agenda, are not confirming its ascendancy.
This week's debate between Prime Minister David Cameron and Nigel Farage, the head of the UK Independence Party, reinforced this impression. Cameron clearly had the best of exchanges over economics but did not land a decisive punch. Farage struggled with his rhetoric that tipped from anti-immigration into scare-mongering and racism.
Instead, the pattern this week has been of suddenly-emerging issues that could stick with at least some voters, having a yet-to-be-determined impact.
Conservative MP Sarah Wollaston's high-profile departure from the Leave campaign over the future of the National Health Service could be telling. Her decision put the NHS into the debate for the first time. Wollaston, the Commons Health Select Committee chairwoman, also damaged Leave when she said --- correctly --- that the campaign has been making false claims about how much Britain will recoup from the EU if it departs.
On Thursday two former Prime Ministers, Tony Blair and John Major, took headlines with their statements that Brexit would de-stabilize the political settlement over Northern Ireland. They were immediately confronted by Northern Ireland's Democratic Union Party, which is hostile to the EU over a range of social issues. However, if Northern Ireland voters are swayed both by security and by the economic damage of Brexit --- the region is one of the largest beneficiaries of EU aid --- then their verdict, shown in polls to be the strongest for Remain, could be decisive on 23 June 2016.
.And then there is the flurry over the extension to voter registration by 48 hours to midnight Thursday, following Tuesday's collapse of the Government system for enrolling. Claims are circulating that one million people have registered this week, with almost 400,000 signing up after the initial deadline.
Leave's senior officials are threatening legal action to overturn the extension. That is unlikely to succeed, but it points to the political significance: the campaign fears that those registering late are more likely to cast their votes for Remain.
If they are right --- and we lean towards that point of view --- then this development could be far more important than any poll snapshot this week.
Professor Scott Lucas
Professor of US Politics and International Relations
Department of Political Science and International Studies