So the EU now sees a deal as possible. It says the UK has made a key concession:

Barnier said Downing Street now accepted the principle that as either side develops their environmental, social and labour standards over time there should be a way to ensure that trade flows are not distorted by the failure of the other to reciprocate. He described the solution as “unilateral measures”, or tariffs, which would probably be applied after a period of arbitration.


I think that is key to any deal. Boris can claim a success because the UK is not automatically bound to EU changes. Equeally the EU ican claim a success in saying it can impose tariffs. Both sides being able to claim a success is very useful in negotiations.

Now the EU does not like this idea on fishing:


The UK has now suggested that pelagic fish are removed from any deal with Brussels and that shares are instead negotiated through the North-East Atlantic Fisheries Commission, of which Iceland and Norway are members. Pelagic fish refers to species that swim closer to the surface and accounts for approximately 80% of the value of fish caught by EU fleet.


However, even the the EU is unhappy, that hides an important UK concession: the UK would not be the sole arbiter of who can catch what fish. So this "UK waters are for the UK" has grown more subtle.