Special leave is granted only where a question of law is raised that is of public importance; or involves a conflict between courts; or "is in the interests of the administration of justice".

A privilege should operate, however, only where "necessary to achieve its purpose," and an invocation of the attorney-client privilege should not go unexamined "when it is shown that the interests of the administration of justice can only be frustrated by [its] exercise."

Speaking today before the House of Lords, Lord Mackay said the legislation would set out broad objectives "designed to further the interests of the administration of justice, to increase access to justice and to extend the range of those possessing rights of audience before the courts."