Building supplies company Carter Holt Harvey is waging a last-ditch legal battle to avoid being landed with the bill for repairing hundreds of leaky schools.
The company is asking the Supreme Court to apply the 10-year limitation on claims under the Building Act, and throw out the Education Ministry's claim that it was negligent in failing to warn schools its plywood cladding product might not work as intended.
Education ministry lawyer James Farmer told the court this morning that if Carter Holt did not know about the problems with the product, Shadowclad, it should have.
He said manufacturers always knew more about their products than consumers - but where there was a major latent problem with one, the size of that information imbalance became very important.
If Carter Holt's case succeeds, about 600 of the 890 buildings involved will be removed from the action.
Meanwhile, the ministry is cross-appealing a Court of Appeal ruling that it can not sue on the basis that Carter Holt misstated claims about Shadowclad.
The case began three years ago, when the ministry launched a one-point-five-billion-dollar action against the company and two other cladding manufacturers - James Hardy and CSR.
It has since reached confidential settlements with the other two companies.