The British people have spoken. Just over half of those who voted in the referendum supported leaving the EU. Although their votes are not legally binding, politicians of all parties have agreed that they will follow their instructions. The big question is “what is next?”

I was in Norway on the night of the 23 June 2016. Ironically, given the dominance of migration in the debate on EU membership, I was attending a major conference on migration and health. I was phoned about 5 am by a journalist who asked me what next? I didn’t have an answer. She understood, and she was also audibly in shock. A few hours later I had to speak to the over 400 people at the conference, many of whom had dedicated their lives to supporting migrants. What was I to say? Again, I had no idea. All I could do was to thank them for everything they do, making a stand against the hatred and division that had been so prominent in the UK in the preceding weeks. The British in the audience were, like me, in shock. Some, including one of my closest Belgian colleagues, were particularly affected, having worked closely with Jo Cox. Together, we remembered her and the migrants she cared so much for.

I’m writing this a few hours later. David Cameron has declared his intention to resign. The pound and the London stock exchange have both fallen through the floor. Social media carries accounts of British tourists unable to use their cards in Greek ATMs. It is clear that those in the Remain camp who predicted financial meltdown got it wrong. The reality is even worse.

But what about health? Again, I have no idea. Within an hour of the final results, Nigel Farage, interviewed on ITV, said that the widely quoted £350 million a week contribution to the EU budget, a figure dismissed as nonsense by everyone who understood the EU’s budget system, would not in fact be spent on the NHS. He described the claim that it would, which had been at the heart of the VoteLeave campaign, as a “mistake”.

Of course, it was only one in a long list of “mistakes” made by those advocating Brexit. And here we need to make an important distinction. Commentators have sought to portray both sides as peddling untruths. Would every household really lose £4,300 per year, as Remain claimed? Of course not? But how do you explain complex models and confidence intervals in a media bubble dominated by six second sound bites? What was in no doubt, and what has subsequently been confirmed, is that the British economy would suffer a severe hit. In contrast, VoteLeave’s claims about Turkey’s accession, the UK’s contribution, and an EU army, were straightforward lies. So what is the VoteLeave plan?

Who knows? We don’t even know whether they want to increase or decrease immigration, which was at the heart of their arguments. But we now urgently need some answers. Joining the EU is difficult enough, but at least there is an agreed goal. Countries must implement the acquis communitarire, the accumulated body of EU law. But leaving will be far more difficult as we lack either a road map or an agreed destination. And worse, successive job losses in the civil service, including, in the Department of Health, some of the few people who actually understand the EU, make one wonder whether we actually have the ability to do it.
One possibility would be the Norwegian model. That would ensure access to the single market and many of the benefits of EU membership. But it would also require that we accept free movement of people and continued contributions to the EU budget, with the Norwegians actually paying more per head than the UK, as well as acceptance of almost all EU legislation. It is difficult to reconcile this with the “benefits” claimed by VoteLeave.

If we are really to “take control,” we would have to cut ourselves off to a much greater degree, accepting not just tariff barriers but also the vast paperwork that goes with them. My daughter, on a gap year, recently posted her climbing boots home from the USA. I had to fill out a four page customs form. If we are to control our borders, keeping those with a criminal record out, we will need to establish an ESTA type system, such as that operated by the USA, Australia, and now Canada. Inevitably, our European neighbours would retaliate. Those thinking of stag nights in Prague who have, at some point in their youth, accepted a police caution, might reflect on that. Spanish ministers have already said that British pensioners may lose their entitlements to healthcare and even to long term residence. So we might replace all the EU migrants providing healthcare with retired Britons who will be using it, or whatever is left given the damage to the economy.

Then there is the question of what policies a British (or more likely, English and independent Scottish) governments will pursue. As Sir John Major noted, the NHS is about as safe in the hands of some leading supporters of Brexit as a pet hamster is with a hungry python.

Before we can even begin to think about the implications for health, we need an answer to these questions. Anything else is simply guess work. The only one thing that is clear is that, for public health, healthcare, or medical research, whatever happens will be an awful lot worse than what we have at present.

Martin McKee is professor of European Public Health at the London School of Hygiene and Tropical Medicine.