The UK Court of Appeal has reset the threshold for asbestos-related cases, which could pave the way for thousands of potential claims.

Lord Justice Jackson said the High Court judge in Bussey v Anglia Heating Ltd had felt ‘constrained’ by relying on data that was never intended to be used as a yardstick for making claims.

Veronica Bussey, whose husband David died in 2016 of an asbestos cancer, appealed the decision. The Court of Appeal has now found in her favour, allowing her to seek damages from her husband’s former employer – even though the asbestos exposure he endured was below the legal limits for a claim.

Guidelines produced 40 years ago about acceptable levels of asbestos fibres in the air have been used as the test for assessing the claims of victims since the ruling in a 2011 legal case, Williams v the University of Birmingham.

This latest ruling is being hailed by claimant lawyers as an acknowledgment the application of historic data is wrong, and that the courts have wrongly applied the measurements as a guide to employers of a so-called ‘safe’ level of asbestos in which people could work.

Caroline Pinfold, an industrial disease solicitor at London firm Fieldfisher, who represented Veronica Bussey, said: “These data that measured levels of asbestos fibres in the air have been wrongly applied by employers and their lawyers to deny or delay claimants the compensation they deserved. I know the ruling will come as a huge relief for mesothelioma sufferers and their families who have had their cases put on hold waiting for this decision.”

Adrian Budgen, head of the asbestos-related disease team at law firm Irwin Mitchell, said: “We very much welcome the findings of the Court of Appeal, that once a risk of injury was identified, employers ought to have taken steps to minimise risks of injury to employees. The judgment now means that many other victims of asbestos disease who find themselves in a similar position to David Bussey may now be able to access the justice they deserve.”