The real issue isn’t with the state of M&S’s knickers, it’s with privacy.
Someone sent a private email to a company, then someone in the company leaked it to the press. I don’t really think that it counts as ‘public interest’ in the way the whistleblowers are protected.
Instead someone has breached this private communication because they saw a ‘good story’.
I understand (and I’m no lawyer) that email doesn’t have the same protections of written, posted, physical mail. In which case this leak might not be illegal, but it is immoral.
One law that would have been broken is that whoever copied the email to the press would have breached the copyright of Mr. Paxman. By making an unauthorised copy of the email the leaker has made a ‘pirate’ copy of Mr. Paxman’s work.
If I were Sir Stuart Rose (Head of M&S) I’d be wondering who leaked this email, and if this person of dodgy morals has been leaking any business secrets.