What are the auditor independence issues surrounding the provision of external auditing services, internal auditing services, and management consulting services for the same client?

What are the auditor independence issues surrounding the provision of external auditing services, internal auditing services, and management consulting services for the same client? Develop arguments for why auditors should be allowed to perform these services for the same client. Develop separate arguments for why auditors should not be allowed to perform non-audit services for their audit clients.