Because the Speech or Debate Clause was modeled on article 9 of the English Bill of Rights, U.S. courts have long looked to English practice and precedent as a guide to its interpretation. This approach is reflected in the very first case to consider the Clause, Kilbourn v. Thompson, 103 U.S. 168 (1881), where the Court observed that “while the framers of the Constitution did not adopt the lex et consuetudo of the English Parliament as a whole, they did incorporate such parts of it, and with it such privileges of Parliament, as they thought proper to be applied to the two Houses of Congress.”
In the British courts there historically has been a prohibition against taking cognizance of matters occurring in Parliament, apart from duly enacted statutes. The concept underlying this rule appears to fall somewhere between a kind of comity (it would be disrespectful for judges to pronounce on matters being debated in Parliament) and a more absolute jurisdictional bar. The latter idea is sometimes referred to as “exclusive cognizance,” and, as explained by the U.K. Supreme Court in Chaytor, “was originally based on the premise that the High Court of Parliament had its own peculiar law which was not known to the courts.”
The British practice has been modified in modern times. For example, in 1980 Parliament adopted a resolution that permitted reference in court to certain parliamentary papers. Then in Pepper v. Hart, 1 AC 593 (1993), “the Law Lords set aside the very old rule that debates in Parliament ought not to be cited in court as an aid to the construction of the Acts which were shaped by the debates.” William McKay & Charles Johnson, Parliament & Congress 511 (2010). Even so, it remains impermissible to consider parliamentary debates for other purposes, such as determining whether Parliament’s reasons for adopting legislation were consistent with the European Convention on Human Rights. Id. 512.
One might think that the British principles of comity and exclusive cognizance would support a broad nondisclosure privilege. Compelling the production of parliamentary records could be viewed as a type of inappropriate judicial notice or scrutiny of parliamentary proceedings. Similarly, it might be viewed as a violation of principles of comity or mutual respect between the judicial and legislative branches.
Although I have not come across any case law on point, a couple of non-judicial precedents shed some light on the subject. The Joint Committee on Parliamentary Privilege, set up in the late 1990s to study the need for modernizing British law on parliamentary privilege, recounts this episode:
Sir Donald Limon, then Clerk of the House of Commons, drew attention to a court action brought against the House of Commons by a disappointed contractor for work on Portcullis House, the new parliamentary building opposite Big Ben. Select committee papers relevant to the contract had been included (with the permission of the House of Commons, secured by motion) in the documents exchanged between the parties. This met the obligation to disclose, but left unresolved the crucial question of how the disclosed material could, if relevant, be used in the course of the trial. Article 9 precluded such use. Unlike its non-statutory privileges, the House of Commons had no power to waive this statutory provision.
Joint Committee Report ¶ 254 (1999). The Joint Committee distinguishes here between the use of privileged documents, on the one hand, and their disclosure in litigation, on the other. The former is covered by article 9, while the latter is not. Note that the report leaves open the possibility that disclosure would be covered by another, non-absolute, privilege.
Another example is the protocol issued by the Speaker of the House of Commons to govern situations in which warrants were issued for searches within the precincts of Parliament (this followed a publicized case in which the police searched the office of a prominent MP). The protocol provides for advance notice of any parliamentary search and further provides that
The Speaker may attach conditions to such a search which require the police to describe to a senior parliamentary official the nature of any material being seized which may relate to a Member’s parliamentary work and may therefore be covered by parliamentary privilege [in which case] the police shall be required to sign an undertaking to maintain the confidentiality of that material removed, until such time as any issue of privilege has been resolved.
See British House of Commons Note on Parliamentary Privilege and Individual Members 10 (Feb. 10, 2010).
Again, this suggests that mere disclosure of legislative materials does not itself waive or violate the privilege. Accordingly, legislative materials seized in a search can be dealt with after the fact by negotiation between the House of Commons and the police (note that the individual MP whose records were seized is given no formal role in this process).
The British protocol contrasts with the approach of the D.C. Circuit in U.S. v. Rayburn House Office Building, 497 F.3d 654 (D.C. Cir. 2007), where the court held that the Speech or Debate Clause required that legislative materials be segregated and removed before law enforcement authorities seized evidence from a congressional office pursuant to a search warrant. Because the Rayburn court found that Speech or Debate encompasses a nondisclosure privilege, the individual Member, rather than the legislative body alone, may assert the privilege.
If British practice does not support the existence of a nondisclosure privilege, the U.S. Supreme Court is unlikely to recognize one. The Court has emphasized that the Speech or Debate Clause was not intended to sweep as broadly as the privileges enjoyed by the British Parliament. See U.S. v. Brewster, 408 U.S. 501 (1972) (“Although the Speech or Debate Clause’s historic roots are in English history, it must be interpreted in light of the American experience, and in the context of the American constitutional scheme of government, rather than the English parliamentary system. We should bear in mind that the English system differs from ours in that their Parliament is the supreme authority, not a coordinate branch. Our speech or debate privilege was designed to preserve legislative independence, not supremacy.”).
U.S. courts have not recognized concepts such as “exclusive cognizance,” and have rejected the notion that the Congress inherited the “lex et consuetudo” parliamenti, a separate law and custom of Parliament unknown to the ordinary courts. If nondisclosure is not incorporated under article 9, it would not likely be encompassed by Speech or Debate. Moreover, U.S. courts have less reason to adopt a nondisclosure privilege because they have never observed a prohibition on judicial consideration of legislative proceedings. Federal courts routinely consider and scrutinize congressional proceedings (and have been known to question legislative motives).
Thus, British practice and precedent would seem to cut against recognition of a nondisclosure branch of Speech or Debate.