Special Immigration Appeals Commission Act 1997 created the Special Immigration Appeals Commission (SIAC) and a system of "Special Advocates". SIAC hears a specified range of appeals - e.g. where a "control order" is made by the Home Secretary. For cases heard by SIAC, the 1997 Act abrogated many of the usual rights which appellants have before the courts. An appellant may appoint his own legal representative but the Attorney-General may appoint an advocate to represent the interests of the appellant. The evidence against the appellant is only shown to the "Special Advocate" and the appellant and his appointed legal representative may be excluded from the proceedings. Although the special advocate is engaged to protect the interests of the appellant, he or she does not actually act for and cannot normally take instructions from the appellant.
The use of "Special Advocates" has been extended to other areas where it is argued that disclosure of evidence might harm "the public interest" - (i.e. national security; international relations; detection and prevention of crime etc). Examples of the growing use of Special Advocates may be found in: Prevention of Terrorism Act 2005 Schedule 1; Counter-Terrorism Act 2008 Schedule 7; Parole Board Rules 2004; Employment Tribunals Regulations 2004 Rule 54(2).
In all instances where Special Advocates are used, there is statutory authority for their use. However, in Al Rawi and others v Security Service and others  EWHC 2959 (QB) Mr Justice Silber ruled that special advocates could be used in civil claims for damages. That decision has now been very firmly overruled by the Court of Appeal in Al Rawi and others v Security Service and others  EWCA (Civ) 482
For the time being, there will be no special advocates in civil cases outside of the statutory schemes. Their use hides the process of justice from the public view and cuts across one of the oldest precepts of the law that "Justice must not only be done: but must be seen to be done". Jeremy Bentham once said that - "In the darkness of secrecy sinister interest and evil in every shape have full swing." In connection with the special advocates system that might be taking things rather too far - (e.g. SIAC publishes judgments) - but there is considerable reason for concern about the growth of this procedure. My guess is that it will not be long before some statutory scheme is introduced for civil cases unless, of course, the Supreme Court overrules the Court of Appeal.
See also Attorney-General's Office
See Offensive against closed justice