It looks like they don't wish to be bullied by the EU, seeing what has happened with AstraZeneca.
They have signed a contract with the UK, but they are sandbagging on the EU. They are saying they can't source all the ingredients they need yet.
Maybe. But it's pretty obvious they aren't signing the contract because they know how the EU will interpret it once the ink is dry.
So the EU's terrible behaviour towards AZ has damaging consequences for the EU's people.
Maybe they should ask the UK to help them figure out how to do this. It all works a bit like a butcher's shop...