The Court of Appeal has recently applied the rarely invoked "unambiguous impropriety" exception to without prejudice ("WP") privilege, to find that a written settlement offer conveyed through a mediator following an unsuccessful mediation was not protected by WP: Ferster v Ferster  EWCA Civ 717.
Communications in connection with a mediation (including when the mediator acts as a conduit for negotiations after the mediation) will of course normally be protected by WP privilege. However, one of the narrow exceptions to the WP privilege is where the communication involved some 'unambiguous impropriety', in the sense of an attempt to abuse the protection afforded by the privilege. In the present case, the Court of Appeal found that correspondence conveying a settlement offer on behalf of the claimants constituted an unambiguously improper threat against the defendant in the nature of blackmail and, as such, was not protected.
The decision serves as a reminder that WP privilege cannot be used as a cloak for impropriety. It also underlines the fact that there is a distinction to be drawn between the use of proper leverage in the context of settlement discussions and the making of improper threats. The courts will take a dim view of the latter. Read more commentary on the decision here.