This much is very clear:

If UK doesn't reach a deal with EU to allow #AstraZeneca to start exporting vaccine doses from its 2 🇬🇧 sites to 🇪🇺, the EU will block any attempt by AZ to ship doses made in 🇪🇺 to 🇬🇧 to make up for UK's current shortfall.

— Dave Keating (@DaveKeating) March 23, 2021