In short, where a sum is "due" by virtue of an architect's certificate or a contractor's application, the paying party now has to serve a withholding notice under the Construction Act, not only where they wish to cross-claim for liquidation or other damages, but also where all they want to do is challenge the amount that is "due" on pure valuation grounds.
Failing to serve the correct notice will be disastrous. The common law right to abate without a notice has now been summarily removed. Bingham is certainly right in his final sentence: "I suggest we send all employers on a training course".
Ian Yule, partner, Wragge & Co, Birmingham.