Today the Court of Appeal handed down judgment in the case of Cartwright v Venduct Engineering Limited  EWCA Civ 1654. The sole substantive judgment was provided by Coulson LJ, now of course the Deputy Head of Civil Justice. The result of the appeal is to uphold the decision of Regional Costs Judge Hale made below: the reasoning of which Coulson LJ paid tribute to.
Accordingly although in principle, a successful co-defendant may seek to enforce an award of costs when an order for damages and interest is made in favour of the claimant against an unsuccessful co-defendant, a settlement made with that defendant by a Tomlin Order, by way of part 36 or in correspondence will not trigger the ability to enforce a costs Order. The immediate application of the principle is accordingly likely to be limited to orders made at trial against multiple defendants.
In a curious way, the court has come back full circle to the situation which pertained under the former Legal Aid Acts: where a plaintiff failed at trial against one defendant and succeeded against another, her award of damages was always liable to form a fund out of which she could be ordered to pay the costs of the successful defendant under the statutory test which then applied.