Legal privilege belongs to the lawyer’s client and not to the lawyer. There are two types:

Litigation privilege - this protects confidential communications created for the dominant purpose of actual or pending litigation. It applies to documents created by and passing between (a) lawyer and client / third party eg:

Emails or letters to a law firm from the director or manager of its client company created as part of the effort to resolve the dispute.

Communications from the client’s surveyor or engineer to the solicitor relating to a construction dispute on which they are providing information or technical assistance to the solicitor.

and also between:

(b) client and third party – communications between the client’s staff and the surveyor or engineer relating to the resolution of a dispute. This is as opposed to communications of an operational nature before events gave rise to the prospect of litigation.

Legal advice privilege - protects confidential communications passing between the lawyer and the client only, and created for the dominant purpose of seeking and receiving legal advice. It does not apply to communications with third parties.

Legal privilege is lost if it is waived by the client, for example by expressly agreeing to waive it or by broadcasting the information to a wider audience so as to render it no longer confidential. An example would be where legal advice was published on the company’s website or to staff who are required to be shown the advice.

Only those persons in the organisation whose job it is to communicate with the lawyer, on the particular topic or generally, are regarded as “the client”. There is a need to consider who qualifies. For example:

An-house lawyer communicating with an external lawyer
Senior members of a project team communicating with either an in-house or external lawyer
A relevant board director doing likewise

It is wise for companies to follow these guidelines:

Those individuals with the definition of “the client” should not copy to all and sundry the documents (emails, memos, letters, reports, etc) for which privilege is sought.
Other staff else should communicate orally with those persons (ie no emails!) on topics for which privilege is desired, and should only go into print when expressly requested by someone who is “the client”.
All persons should when creating relevant documents mark them “Privileged and confidential - created for purpose of obtaining legal advice”.
Companies should discourage written commentary, discussions and questions on the legal advice and be careful not to repeat it in meeting minutes or notes.
Documents which discuss settlement of a dispute should be marked “Without prejudice”.

This expression is used to avoid the contents of a document or conversation from binding the author or speaker. Typically it is used when a person indicates a willingness to move from his stated legal position as part of a negotiation eg “although we are suing [or are about to sue] you for £3m we will settle for £2m if you pay us in the next thirty days”.

If this offer is not accepted by the other party and the litigation commences / continues, that other party might use it to their advantage, by seeking to persuade the court that the £3m claim is inflated. If the offer is made without prejudice then the details of it cannot be disclosed to the court.

These expressions prevents any hostile party from arguing that the author of a document or speaker putting forward a proposal is not bound by the document / proposal until he / his employer has signed a document.