A couple of thoughts about this piece by @JohnRentoul.
First, as someone who has seen a lot of brilliant advocacy in the higher courts, I’m not sure that this antithesis between “forensic” and the killer and theatrical punch line quite holds up. 
Especially in public law, the law - and successful advocacy - isn’t all about dry technical detail. Yes, technical detail matters and you need to deal with it effectively. But you also need to be putting forward an account of the law that rings true, holds together, & makes sense
Provided you have built up to it, and got the basis for it, a good punch line, turn of phrase, or peroration can be brilliantly effective in the higher courts.
Judges are, after all, human. And rhetoric in the proper sense - the skill of presenting arguments persuasively to the audience you have - is at the heart of the advocate’s art.
The main difference between a great court advocate and some of our politicians isn’t rhetoric: it’s that the great court advocate is on top of the detail, builds the case on careful argument and facts, and has a horror of misleading their audience (the court).
But the fact that some of our politicians fall well short of those standards doesn’t mean that a politician who meets them will be any less effective as a politician. (As one cabinet minister seems ruefully to accept.)
Second, a quite different point.
It’s important to be clear that imposing environmental conditions on Covid 19 State aid is entirely compatible with EU law.
Member States are always entitled not to give State aid, and if they give authorised aid (eg under the Covid 19 framework) to impose extra environmental conditions in it before handing it out.
And the non-Covid 19 State aid rules already permit (without notification to the Commission) large amounts of aid for eg environmental or social reasons. The UK tends to under-use these provisions: but that’s its own choice.
