Would I be correct in thinking that if BA win that one it would set a precedent in UK law meaning no Union can ever again afford to threaten an airline with Industrial Action?
My layman's understanding is that the precedent has already been set (ITWF vs Viking) it applies only if the industrial action they are taking is intended to restrict the company's ability to operate within other EU member states through subsidiary companies and the industrial action taken is disproportionate to the goal being sought.
This is just my understanding of the implications, I don't hold any qualifications in the field of law so I could have written complete b*****ks. From what I've read the UK Appeals Court still has to make a final judgement on Viking by applying the ECJ judgement to UK law.