Which Course of Action Should You Follow

Which course of action should you follow?
a) You have to decline as it is a definite conflict and is effectively ruled out by the ethical guidelines of your RSB.
b) It is a conflict of interest and there is a danger of being involved in management decision making which is prohibited specifically by the ethical rules. Providing separate teams were used and the internal audit was overseen by another partner it would be possible to take on the work. The external audit team must remain independent of the internal audit team and there must be no communication between them except at arm's length during the course of the audit.
c) It will help the audit by giving you a better insight into the company so could be looked at as an extension of the external audit. You could use the same team and simply amend the external audit programs accordingly.
d) If this was the USA it would be illegal and cases such as Enron demonstrate the dangers of being seen to go soft on the company because of all the lucrative non audit work - best to avoid the whole thing even if it means a rival firm becomes involved with your client.