This was the reason why KLM is still technically a Dutch company too (much to the annoyance of the French and the holding in Paris..) They have a structure that ensure that for traffic right reasons they are Dutch. Took a while to set up and is not easy to replicate for BA in case for a No deal I guess but then I assume they have spend a LOT of money on this already at IAG board level to find a way out of this mess...