The Court of Appeal in Heron v. TNT (UK) Ltd  EWCA Civ.469 considered whether or not solicitors who failed to obtain ATE Insurance for their client in a personal injury case and who failed to admit that to him - but without any conscious impropriety - should be subject to a non-party costs order. The defendant's insurers argued that thereby the solicitors had become a "real party" to the litigation, the person "with the principal interest" in its outcome or that they were acting primarily for their own sake - all phrases derived from the main authorities. The court, upholding the judgment below, decided they had not. As Leveson L.J. put it, if the defendant was right,
"every act of negligence by a solicitor in the conduct of litigation (thereby giving rise to a conflict) which means that an opposing party incurs costs which might not otherwise have been incurred would be sufficient." The law does not go that far.