AA
Interesting and relevant question.
A further question is what is the source of the legal advice - 'in house' government employed lawyers, a firm of solicitors or Counsel?
Doubtless the MOD will claim legal professional privilege. Not sure about the current state of the Law in the UK. But in Oz, there's recent case law that casts doubt on any legal professional privilege claim made by government employed lawyers, if they don't hold a practicing certificate.