## Facts

- During World War II, the Home Secretary made a detention order against Robert Liversidge under Defence (General) Regulations 1939, Regulation 18B(1), which allowed detention if the Secretary of State “has reasonable cause to believe” a person has hostile associations and control is necessary.
- The order recited that the Home Secretary had reasonable cause to believe Liversidge was a person of hostile associations and directed his detention; Liversidge was held in Brixton Prison.
- Liversidge received no particulars of the evidence or grounds said to constitute “reasonable cause,” and none were disclosed to the court.
- Liversidge sued the Home Secretary (and successor) for false imprisonment and sought declaratory and injunctive relief challenging the detention’s legality.
- In pleadings, the government relied on the detention order and refused to plead particulars of the grounds; Liversidge applied for an order requiring particulars.
- The lower courts refused to order particulars, treating a facially valid order as sufficient unless the detainee could show invalidity (e.g., bad faith).

## Issues

1. Whether Regulation 18B(1)’s phrase “has reasonable cause to believe” creates an objective, court-reviewable condition requiring proof of reasonable grounds.
2. Whether, in a false imprisonment action challenging detention under Regulation 18B(1), production of a facially valid detention order is a prima facie complete defence, placing the burden on the detainee to prove invalidity, and whether the minister must provide particulars of the grounds.

## Decision

- The House of Lords dismissed the appeal and upheld refusal to order particulars (majority; Lord Atkin dissenting).
- The majority construed “has reasonable cause to believe” as effectively subjective: it was enough that the Secretary of State honestly formed the requisite belief; courts would not examine the adequacy of the underlying information.
- A detention order regular on its face was treated as a prima facie complete defence to false imprisonment; the plaintiff bore the burden to impeach the order (e.g., by showing bad faith).
- Because the court would not test the sufficiency of the intelligence supporting the belief, the Secretary of State was not required at the pleading stage to particularize the grounds for the belief.

## Legal Principles

- Where a statute or regulation conditions executive action on the minister “having reasonable cause to believe” in a national security context, courts may treat the condition as satisfied by the minister’s honest state of satisfaction rather than an objective, evidentiary standard.
- In civil claims for false imprisonment arising from detention under emergency powers, a facially valid detention order can operate as a prima facie complete defence, shifting the burden to the claimant to show illegality (including bad faith).
- Judicial reluctance to compel disclosure of security-sensitive grounds may limit interlocutory procedural tools (such as particulars) when the legality inquiry is confined to formal validity and absence of bad faith.
- Dissent (Atkin): “reasonable cause” ordinarily imports an objective standard; courts should require sufficient disclosure to test legality and should not rewrite statutory language to insulate executive detention from review.

## Conclusion

The House of Lords’ majority treated wartime detention under Regulation 18B(1) as turning on the Home Secretary’s honest satisfaction that reasonable cause existed, making a facially valid order a strong defence to false imprisonment and eliminating any general requirement to plead or disclose the grounds, while the dissent insisted the language required objective judicial scrutiny.


Liversidge v. Anderson, [1941] 3 All E.R. 338 (H.L. 1941)