Privileges are divided into two groups: public interest privilege and private privilege. The Crown has always been able to claim public interest privilege in relation to secrets of the state and other matters whose confidentiality is essential to the functioning of the public service (see Crown privilege; public interest immunity). A similar privilege may be claimed by private parties when some overriding public interest is involved. Under Part 31 of the Civil Procedure Rules a party may make a without notice application for an order permitting him to withhold disclosure of a document on the ground that disclosure would damage the public interest. See disclosure and inspection of documents.
Private privileges include the privilege against self-incrimination, (according to which a witness may refuse to answer a question the answer to which might tend to expose him to criminal proceedings) and legal professional privilege. Legal professional privilege includes legal advice privilege (which protects confidential communications between lawyers and clients made with a view to obtaining or providing legal advice) and litigation privilege (which protects documents prepared by lawyers, and communications between lawyers and third parties, made with a view to existing or contemplated litigation). A privilege also attaches to without prejudice communications made as part of an attempt to settle a claim. See also marital privileges.