In Sprecher Grier Halberstam LLP and Another v Martin Walsh [2008] EWCA Civ 132 the Court of Appeal considered the scope of witness immunity from suit.

We recite paragraphs 39 and 40 taken from the House of Lords:

39. The doctrine is well settled. In Watson v M’Ewan [1905] A.C. 480, 486, the Earl of Halsbury L.C. said:
“By complete authority, including the authority of this House, it has been decided that the privilege of a witness, the immunity from responsibility in an action when evidence has been given by him in a court of justice, is too well established now to be shaken. Practically I may say that in my view it is absolutely unarguable – it is settled law and cannot be doubted. The remedy against a witness who has given evidence which is false and injurious to another is to indict him for perjury; but for very obvious reasons, the conduct of legal procedure by courts of justice, with the necessity of compelling witnesses to attend, involves as one of the necessities of the administration of justice the immunity of witnesses from actions being brought against them in respect of evidence they have given. So far the matter, I think, is too plain for argument.”

40. A more modern exposition of the rationale for the rule is given by Lord Hutton in Darker v Chief Constable of the West Midlands Police [2001] 1 A.C. 435, 464:

“… in order to shield honest witnesses from the vexation of having to defend actions against them and to rebut an allegation that they were actuated by malice the courts have decided that it is necessary to grant absolute immunity to witnesses in respect of their words in court even though this means that the shield covers the malicious and dishonest witness as well as the honest one.”

He added at p. 468: “Furthermore, the authorities make it clear … that where the immunity exists it is given to those who deliberately and maliciously make false statements; the immunity is not lost because of the wickedness of the person who claims immunity.”

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See also: Article dated 14 April 2025 – The doctrine of witness immunity – English law