The EU referendum results so far tonight have been very encouraging for the Leave campaign:

The UK’s EU referendum is proving close but the Remain campaign appears to be failing to pick up enough support outside London to win.

At 0345 BST Leave were ahead by over 500,000 votes, with the English shires and Wales voting strongly for Brexit.

It’s still possible that Remain will end up pulling it out, but as of 11:00 p.m. Eastern supporters of withdrawing from the EU have done better than expected and their opponents have not turned out in the numbers that they need to secure a victory. The Remain side was buoyed early on tonight with reports of new polls that showed them winning by 4-8 points, but then as actual results started to come in Leave began scoring larger-than-expected wins and did better than most people expected in many other places. The anecdotal evidence indicating strong support for Leave in many constituencies appears to have been correct. The financial markets and bettors had too much confidence in predictions of a Remain victory, and have been panicking in response to evidence that they have misread the situation.

Turnout throughout the country was quite high (roughly 72%), which makes Leave’s apparent success all the more remarkable. The conventional wisdom was that Remain would benefit from a high-turnout election, but it seems that Leave has benefited from having many people that don’t normally vote show up at the polls. Turnout in reliably Remain parts of the country (e.g., Scotland) has been lower than anticipated, and that is in keeping with the assumption that Leave supporters are more motivated to vote. The final result will likely be quite close, and Leave has a decent chance of an outright win. If that happens, Cameron will be humiliated, but he may be able to hang on in office for a time because of the support he has received from so many of the pro-Leave Tories. Even if Remain holds on to win by a narrow margin, it seems certain that another referendum on this question will be held in just a few years’ time.

A Leave win would represent an extraordinary repudiation of Britain’s political class, and it would be an unprecedented expression of popular dissatisfaction with the EU. Both of these are healthy and long overdue. While they may have some negative short- and medium-consequences for Britain and the EU, a vote for withdrawal would nonetheless be a welcome outcome.

Update: The BBC projects that Leave will win.