The Leave campaign has spent plenty of time, at least until recently, assuring us we can have the best of all worlds. If you believe them, Britain’s clout will be enough to secure single market access, an end of free movement, no need to accept EU rules and more besides. We will, apparently, be free from all Europe’s supposed downsides and keep all its benefits.

This is pure fantasy, for reasons ably outlined elsewhere. The rest of the EU won’t offer a deal where the UK gets full market access, including services, without taking on EU rules and accepting freedom of movement. The UK may be larger than Norway, and a major partner for the rest of the EU, but they account for 44% of our trade and we account for 8% of theirs: it’s quite clear who needs whom more. Anyway, we’re not going to be allowed to be a member of the single market with no obligation to implement EU rules as a matter of principle. A 64-million strong loophole in the rules of the single market will, reasonably, be seen as flagrant social dumping, and if the purpose isn’t to allow the UK to have lower social and regulatory standards than the EU, then why would we be trying to opt out in the first place? Above all, it would set a baleful precedent for future exits: if Britain could leave, keep everything it liked about the EU and drop everything it didn’t, why couldn’t anyone else? And how long would the EU itself last in such circumstances? The whole project is built on compromise and tradeoffs: Europe can’t afford to unpick the whole bargain thread by thread. So if we leave, the question will be how many trade-offs we choose to make to keep some of what we have now as an EU member.

But it’s worse than that: the very terms of the referendum debate could make even a least-worst Brexit deal impossible. Vote Leave and Leave.EU are currently fighting campaigns where immigration and (narrowly defined) sovereignty take centre stage. How could a post-Brexit Britain, having rejected the very principle of common rules it played a major part in making, then accept common rules on which it didn’t even get a vote? How, having voted against free movement, could it then accept its continuation in return for less influence in Europe and more imperfect access to its markets than before? How on earth could the Leave side defend such an outcome, and how on earth could Britain see it as an acceptable relationship with the EU after Brexit?

The answer, surely, is that it couldn’t. The victorious Brexiteers couldn’t be seen to accept such terms: their own side would tear them apart, and they wouldn’t want to anyway. Many of them have dedicated their lives to tearing down supranational cooperation: why would they readopt it immediately after their greatest victory? People in Vote Leave don’t really think they would: why else are they happy to cite the Canadian free trade agreement (which doesn’t include services) as a favourable model?

Brexiteers’ claims and their stated aims lead inexorably to outright rejection of the single market and a loss of full access. In time, that means a return of barrier after barrier to half our trade, or a slew of standards set by others which we’ll have to meet (again, for less access than we’d have in the EU or EEA), or a bit of both. There’s a destructive dynamic to this campaign on the Leavers’ side: their ideological hostility to the European institutions forces them into ever more uncompromising degrees of separation. The consequence is that abstract sovereignty takes precedence over concrete jobs; marginally reduced immigration trumps the end of single market access.

If you’re voting Leave to secure some middle ground, don’t: not only the preservation of the EU but also the logic of the Brexiteers’ own arguments make it a mirage. Rightly or wrongly, Britain already has a middle ground – outside the euro and Schengen, granted an opt-in on justice and home affairs, but still a major player in the European institutions. We secured that status because we had a seat at the table and a vote on the rules. If we walk away from the table and throw our vote away, don’t expect us to pull it off a second time.