Corrective action process

As an Auditor, at the opening meeting of an external audit, you are informed that a recent internal audit has found many NCR relating to the in-house purchasing department. Corrective action has already been planned. It is therefore suggested that to audit this department again would add no value and asks if you could delete this department from the audit plan and spend more time in the production area. So some issues you would include in the response you would give to this request?