The Claimant and Defendant entered into a contract for the construction and grant of long leases on a development scheme which the Defendant acquired the freehold to. The Defendant was a construction company, and was required under the Contract to proceed with “due diligence” and “use reasonable endeavours” to procure completion by the target date. The Defendant ceased work due to funding difficulties. The Claimant alleged this was a repudiatory breach but did not end the contract for a further 11 months. The Defendant repudiated the contract itself. The court held that the Defendant was in breach of the term of the contract requiring due diligence by failing to carry out the works assiduously or with expedition. It was held that although the breach may not initially have been repudiatory, over time it could become repudiatory if it deprived the innocent party of the benefit of a significant part of the contract. Negotiation over the course of the breach did not mean the Claimant had affirmed the contract. The Judge therefore decided for the Claimant.