why keep sounding the alarm that negotiations cannot be completed by the end of the transition period and continue to use the media to whip pressure to extend?
I don't know if you've actually noticed, but it's not the EU, but rather the IMF which is sounding the alarm bell as of recently.
Or do you throw them all together: eurozone, schengenzone, EU, EFTA, EEA, OECD, IMF, UEFA, ECJ, ECHR, ..
All these continental letter sprews are so confusing, aren't they?
At present the official desire of the UK government is not to extend the transition period and still get a deal along the lines previously agreed in the PD; which was quite a challenging position to start with, but has now become simply impossible due to an urgent and unexpected lack of time as well as resources, which inconveniently for Brexiteers is not to be blamed on Brussels, but on the corona pandemic.
So now basically everybody in the whole wide world wants to know which of the two the UK prioritises over the other one: the date at which the change will happen, or the scetched outline of that change for which they have been planning as good as they possibly could?
If it's the date which will take priority over the form of changes ahead, others may have a few words to say about the consequences of that unilateral choice, as it means they will have to prepare for something radically different (i.e. WTO rules) then what they were preparing for up until now based on what the British government told them in fact, only to revert back to something in between shortly thereafter then, at least if the UK is still willing to go for a FTA with the EU... Not really very respectful, is it? Unless the WTO state suddenly has become the desired end state after all then?
But then all other parties involved would like to be notified of this important change and not be taken for a bunch of fools by the UK on this as well!
The concept of sovereignty is that you can chose to play with whom you want, not that you can expect others to just dance to your tune.