Rejoining the EU can absolutely be done, but I think it's unlikely the UK could join on the terms it had before, I can't see that being accepted in the current political climate in Europe.

In theory, any new country joining the EU has to switch to the common currency, the Euro, something the UK was able to gain an exemption from while still a member along with Denmark, Sweden and a handful of others, a long time ago when the Euro was first introduced.

This has always been an issue when discussing Scottish independence too, given the SNP have always claimed Scotland could rejoin the EU and keep the pound; the EU has always said otherwise.

> https://economy-finance.ec.europa.eu/euro/enlargement-euro-a...

Sweden doesn't have an exemption.

But to join the Euro, it is a requirement to be a member of ERM II for 2 years, and Sweden argues that that is voluntary, and just haven't done it.

You're right that Denmark has an opt-out, though.

On other hand Denmark has pegged their currency to Euro and hold that peg.

Instead of "breenter" it would probably be more realistic for the UK to join up with Mexico, USA, and Canada as a fourth member of that trace bloc. Together they would then have more power to negotiate a favorable trade deal with the EU.

Haven't you followed Trump's tariffs policies at all? He wants big tariffs against Canada and Mexico and almost everyone else.