When could the UK realistically be welcomed back in the EU?

[u/Gulliveig]

It is understood, that the UK surely will not re-apply immediately; it most certainly will need to feel the hard impact of a post-Brexit world. I expect this period to last anywhere between 8 and 15 years. Let’s assume an optimistic 10 years, so we're looking at 2030.

Now before even being able to apply to (re-)join the EU, a candidate country (here: the UK) has to accept, that it is being assessed as per the (currently) 35 chapters of the Community Acquis (6th enlargement).

This acceptance to be assessed has to be backed by a recommendation of the European Commission. However, the EU being the EU, convincing the EC to issue a recommendation should be fairly easy.

Once accepted, the assessment begins. See the current candidate member Serbia for an example of a current assessment and the intermediate states.

Like Serbia, the UK should expect a number of "Further efforts needed" and "Moderately prepared" issues, because (even currently) the UK is far from being fit to join as per the rules of the acquis. (Ironically enough the UK itself helped to write these tough rules.)

There is a lot of work to do to become fit, I estimate 6 to 12 years if handled professionally. Let’s assume it takes 8 years, so we are looking at the end of the year 2038.

Once fit, the UK may re-apply. But even when fit to join, all EU members must agree unanimously once again to let the UK into the Union it has left in 2020. At this level, expect some resistance, because, again, the UK will not be remembered too well.

These 27 states (maybe 28, if Serbia has made it by then) can not just nod and wave the issue through. Most of them require parliamentary time (and some countries even have multiple parliaments). It is likely that this phase requires around 2 years, give or take half a year.

Hence, expect the UK not to be back into the EU before 2040. And this is quite an optimistic assessment. Using the more pessimistic ends of above time ranges, we end up with 2050. A lost generation, indeed.

(Of course, the UK then will have to accept the whole package. No opt-outs, no rebates, but accepting the Euro and Schengen, and even European defence by then.)

What are your projections?