McIlkenny v Chief Constable of the West Midlands (Walker v Chief Constable of the West Midlands, Power v Chief Constable of the Lancashire Police Force, Hunter v Chief Constable of the Lancashire Police Force)

A court has an inherent duty to prevent misuse of its procedure where the misuse would be manifestly unfair or would bring the administration of justice into disrepute. The categories of abuse of process are not closed.

It is ordinarily an abuse to commence civil proceedings which collaterally attack a final decision made against the claimant by a competent court after a full opportunity to contest the issue. This principle extends to an adverse decision of a criminal court and is broader than strict issue estoppel. An exception may arise for genuinely new evidence which could not previously have been obtained with reasonable diligence and which entirely changes the aspect of the case.

Hunter v Chief Constable of the West Midlands Police was an interlocutory appeal arising from one of several parallel civil actions. Hunter sought damages for assaults allegedly committed by police officers while obtaining a confession later admitted at his murder trial. The same allegations had been examined during an eight-day voir dire, after which Bridge J found beyond reasonable doubt that the police had used neither violence nor threats.

Cantley J refused to strike out the civil claims, partly because proposed evidence not called at the criminal trial might conceivably lead another tribunal to accept part of the claimants' case. The Court of Appeal unanimously reversed that decision and struck out the claims as an abuse of process: McIlkenny v Chief Constable [1980] 1 Q.B. 283.

The central question was whether a civil claim seeking to relitigate the alleged police assaults constituted an impermissible collateral attack on the final criminal ruling.

1. Appeal dismissed unanimously. Lord Diplock delivered the leading speech. Lord Russell of Killowen, Lord Keith of Kinkel, Lord Roskill and Lord Brandon of Oakbrook agreed. The Court of Appeal's order striking out the claim against the police was affirmed.

2. Per Lord Diplock, a court possesses an inherent duty to prevent use of its procedure which, despite literal compliance with procedural rules, would be manifestly unfair or would bring the administration of justice into disrepute. The circumstances constituting abuse are varied and should not be confined to fixed categories.

3. Per Lord Diplock, commencing proceedings to mount a collateral attack upon a final decision against the claimant, made by a competent court after a full opportunity to contest the issue, is an abuse of process. That principle was supported by Stephenson v Garnett [1898] 1 QB 677 and Reichel v Magrath 14 App. Cas. 665.

4. Bridge J had necessarily rejected Hunter's allegation of police violence when admitting the confession. Although the voir dire ruling could initially have been reconsidered during the trial, it became final when the trial ended. It could then be challenged only by appeal. The later civil claim raised the identical allegation and was therefore a collateral attack on that final ruling.

5. The fact that the prior decision was criminal did not prevent the abuse principle from applying. A decision against a defendant made to the criminal standard is incompatible with a contrary finding on the same question under the lower civil standard. A decision in the defendant's favour, such as an acquittal, does not have the same consequence.

6. Per Lord Diplock, agreeing with Goff L.J., fresh evidence can justify an exception only under a rigorous standard. It must not have been available at the earlier trial, or obtainable then by reasonable diligence, and must entirely change the aspect of the case. The evidence relied upon by Hunter was previously available or obtainable and fell far short of the required cogency. The less stringent appellate test in Ladd v Marshall [1954] 1 WLR 1489 did not govern a collateral attack in a court of co-ordinate jurisdiction.

7. Lord Diplock further stated, with the agreement of the House, that the expression issue estoppel should remain confined in English law to its established civil meaning involving the same parties or their privies. Whether the present abuse also bore that label was immaterial. He also explained that section 11 of the Civil Evidence Act 1968 permits a conviction to be rebutted on the balance of probabilities, while section 13 gives conclusive effect to a relevant conviction and reflects the policy against collateral attacks.

• House of Lords: The appeal was dismissed unanimously and the Court of Appeal's order was affirmed: [1982] AC 529.
• Court of Appeal (Civil Division): The police appeal was allowed unanimously. The statement of claim against the chief constables was struck out as an abuse of process: McIlkenny v Chief Constable [1980] 1 Q.B. 283.
• High Court: Cantley J had refused the applications to strike out the parallel claims, holding that strict issue estoppel did not arise and that the proposed additional evidence might conceivably lead another tribunal to accept part of the claimants' case.