Honestly... watch this, and read the book if you have time, its very very interesting and quite a few people on here talking about trade in the future need a better understanding of how trade works globally.Yes, it will need Argentina to agree to our membership but stranger things have happened before when it comes to trade.
the current trading terms, including quotas, are part of the WTO schedules.
The point I made about 20%-25% of our trade is shuffling freight through EU ports won't cause delay. The container destined for acme Ltd will arrive in Flelixstowe on schedule, except that the invoice will be from China instead of from the EU.