If you talk to people about the UK re-joining the EU, those who are not in favour tend to come up with three arguments that they think terminate the discussion.

First, we will have lost the rebate, so we’ll have to pay a massive contribution to the EU budget.

Second, we will have to join Schengen.

Third, we will have to adopt the Euro.

It’s worth taking a detailed look at these, because things are not necessarily as they seem.

Leavers love to focus on the gross contribution to the EU budget, the infamous £350 million a week that featured on the side of a big red bus in 2016. As we all know, this is not the same as the net contribution, which is what is left after you subtract from what we paid in all the money that we used to get back, not just through the rebate but through the agricultural, environmental and regional funds. Even this calculation does not tell the whole story, because it misses all the non-budgetary advantages we used to get from membership which were the main reason for joining in the first place; but at least it puts the budget discussion on a more rational footing that just talking about the gross contribution.

The reason we needed a rebate in the 1980s was that our receipts from the EU budget were not sufficient to balance out the large amount we were obliged to pay in under the revenue system. This complex calculation used to hinge on things like GDP, the VAT base, agricultural efficiency – a whole series of factors that will likely have changed by the time we re-join. To put it bluntly, Brexit is likely to have done so much damage to the British economy that our GDP will have shrunk in comparison with the EU average. This means not only that our gross contribution will be lower, but also that our ability to receive funds from various EU support budgets will have increased. I do not know, of course, whether this effect will be large enough to turn us into a net recipient of EU funds, but it will certainly change the calculation. Not having a rebate is not, therefore, the clinching argument the Leavers think it is.

When it comes to Schengen and the Euro, people tend to assert that membership of both is automatic for all EU members, so we would have to be in both if we were to re-join. That is not the case. There are many existing members that do not take part in either policy.

The exceptions are not, as is commonly supposed, limited to temporary transition measures for the new members in Eastern Europe but include permanent exceptions for several older members as well.

Ireland and Cyprus are not in Schengen, while Denmark and Sweden are not in the Euro.

If the UK were to re-join the EU, the negotiation would not be about whether we should join either policy immediately on accession, but rather about whether we would adopt a long-term commitment to join when conditions were right. As long as we were to retain a say in whether the conditions were met, we should be able to remain outside either policy for as long as necessary. It goes without saying that both Schengen and the Euro are not all downside but also have considerable advantages.

The UK has never been able to have a rational conversation about the balance of advantage to either policy because logical thought was always drowned out by political noise. Perhaps the day will come when a more balanced discussion will be possible.

These arguments are complex and not easy to transmit to people who will not be willing to hear them. At all events, however, Re-joiners should not accept that their views can be overridden by sloppy thinking about the conditions for re-joining.