Brexiteers seem to have a 'victim complex' when it comes to the EU.
Whereas the EU is simply adhering to trade deals (that the UK helped form) and quite rightly so.
But here is a simplified version which even simple leavers might understand.
"Leaving the EU automatically means that the UK becomes a “third country” to the bloc.
When the EU did some 40 free trade deals with the likes of South Korea, Mexico and South Africa the agreements stipulated that any produce or manufactured good which passed between them tariff-free had to have genuinely originated in the two signatory countries or blocs.
This stipulation was necessary to prevent other countries essentially free-riding on the deal. For instance, a firm in a third country could export their goods to one of the two parties to the free trade agreement and then re-export goods to the other party without paying the applicable tariffs.
To prevent this happening the two countries in the deal impose “rules of origin” checks on imports. For the UK, while it’s in the EU, this is not a problem. Any UK goods pass through fine. Also, any UK components in EU goods are not a problem at all.
But with the UK out of the EU’s customs union the situation is potentially very different. Rules of origin specify that a certain proportion of a good has to have been made in the country or bloc to qualify. The proportion varies with the good in question, but it’s often around 50 per cent. For cars the requirement is 60 per cent.
If, after Brexit, an EU business has used components sourced in the UK, that could potentially push the proportion of the exported EU good under the threshold, meaning it would fail the rule of origin requirement and be forced to pay the standard tariff.
This is why the commission has issued its warning to EU firms to be wary about using UK manufactured goods if they don’t want to have a nasty surprise when they seek to export to third countries with which the EU has a trade deal."
It also means that in order to get individual trade agreement with countries such as these post brexit, we'll have to be very generous with our terms and essentially undercut the EU.
Welcome to the UK - the newest sweatshop country!