When YouGov published its on-the-day poll at 10pm last night, suggesting Remain was four percentage points ahead, I thought we would have a clear result for staying in the EU by now. YouGov's on-the-day poll for the Scottish referendum was one point away from the result, and most of the voting intention polls published before the referendum suggested Remain was ahead, albeit by a small margin.
But when the first results came in from Sunderland and Newcastle, showing much better results for Leave than expected, the whole picture changed, and it is still, at 3.30am, unclear what the outcome will be. Most of the results were better for Leave than the estimates for how well Leave should do if the national result were neck and neck.
The BBC says cautiously that it is too early to predict the outcome, but its "not a forecast", in John Curtice's words, is that Leave has a better chance of winning. Chris Hanretty of the University of East Anglia, Michael Thrasher of Sky News and JP Morgan are all predicting Leave will win.
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If so, this is the biggest disruption of British politics since the Labour Party eclipsed the Liberals after the First World War. It would be hard to see how David Cameron could continue as prime minister, except as a caretaker while a successor is elected.
The important consequence of a Leave vote, if that is what it is, would be a shock to the economy. The pound has already fallen steeply overnight. But politically the significance is that all of the leaderships of the four largest parties in the House of Commons will have been overturned, and that Boris Johnson will probably be expected to lead the nation in the negotiations of the terms of our departure from the European Union.
