In personal injury cases proceedings must be issued at court within 3 years of the date on which the injury occurred or, if later (for instance, where the injury is latent), within 3 years of the date that the injured person had the knowledge required in order to bring the claim (s.14A Limitation Act 1980).
The ‘Atomic Veterans Litigation’ (Ministry of Defence v AB and others  EWCA Civ 1317) concerned injuries alleged to have been caused by atmospheric nuclear tests that took place in the Pacific between 1952 and 1958. Claims were issued by a group of 1,011 ex-servicemen who claimed to have suffered injury through exposure to radioactive fallout. The Ministry of Defence denied liability.
Upon the making of a Group Litigation Order in favour of the Atomic Veterans, 10 lead cases were tried on limitation as a preliminary issue. The trial judge found in favour of the claimants in all 10 cases: five on the basis that the claimants did not have the relevant knowledge of the injury, for the purposes of s.14A, until less than 3 years before proceedings were commenced.
On Appeal it was held, in all but one of the five cases originally allowed to proceed under s.14A, that they were statute barred, as the claimants had relevant knowledge more than 3 years before the claims had been issued. On the question of what exactly constitutes knowledge, the Court of Appeal held that a claimant only needs enough knowledge for it to be reasonable to expect him to set about investigation. In this case the claimants sought to rely on the fact that they were awaiting the results of expert evidence as to the cause of their injuries before pursuing the claims. The Court of Appeal refused to allow them to do so, finding that time began to run for the purposes of s.14A when it was reasonable to the claimants to investigate, not when the result of that investigation was known.