S 111(1) of the Housing Grants, Construction and Regeneration Act 1996, which provided that a party to a construction contract may not withhold payment after the final date for payment of a sum due under the contract unless he had given an effective notice of intention to withhold payment, did not apply to a lawful ground for withholding payment, such as the contractor’s insolvency, when it was not possible in the circumstances for notice to have been given within the statutory time frame.