Maybe the rules had changed, but when I was considering learning to drive in the U.K., I couldn’t use that driving license in the EU unless I had been driving for more than 5 years (or something in that region) and was over 25 years old (again, something in that region).

So you couldn’t pass your driving test then immediately drive abroad.

Edit: I cannot find any detail on that so maybe this isn’t the case any longer. Learn something new everyday :)