Remain has overtaken Leave in the EU referendum, but the outcome will depend on which side can garner better turnout amongst their supporters, according to a new poll.
An OBR poll for the Telegraph found that 51 per cent of voters now support Remain, an increase of four per cent from last month. Meanwhile, Leave has fallen five per cent to 44 per cent.
In an analysis of the poll, Sir Lynton Crosby said "the outcome of the referendum will hinge on which side can better turnout their supporters".
That's in part because the poll shows that the proportion of those who are undecided, or could change their minds before the vote, is small.
As such, as people have made up their minds, the outcome will turn on which side can better rally their supporters to the polling booths.
And while Leave voters continue to be more likely to show up - 70 per cent said they would vote if the referendum was held today - this has fallen from 79 per cent last month.
The proportion of Remain voters who said they would show up has also fallen from 72 per cent to 61 per cent.
But when you combine that with the topline results (51 per cent for Remain, 44 per cent for Leave), voting intention is basically split.
Crosby said: "The fact that the Remain campaign are turning out a smaller proportion of the voters that support their cause, while current voting intention remains neck and neck, shows that the Remain campaign holds greater potential for success if it can effectively identify and motivate its supporters."
"The potential voters each campaign has that are supportive, but not currently intending to vote could be far more influential than the ability of either campaign to win over the small proportion of undecided voters," he added.
What is key is the issue of complacency. If voters believe the outcome is uncertain, each vote seems important, and voters will turn out.
As expectations of remaining in the EU have fallen recently, Remain may therefore be able to capitalise on that uncertainty and make their supporters turn out.