A leading lawyer has warned insurers that a recent, controversial asbestos claim judgment will not let them off the hook.

Earlier this month, the Court of Appeal found Arthur Fairchild's widow Judith could not be compensated after his death caused by mesothelioma in 1996.

The court decided it could not be ascertained which of his exposures to asbestos, by two employers, caused his disease.

It was argued that mesothelioma could be caused by just one fibre of asbestos in the lungs.

Some lawyers claimed the judgment eased pressures on insurers, but Tony Prichard, Weightmans' head of litigation, said the judgment would hit insurers in at least five different ways.

He said the decision would result in claimants "shopping around" for medical advice to best suit their claim, as another medical theory was that the risk of mesothelioma could be increased by multiple exposure.

He said claimants could also claim provisional damages when they developed pleural plaque, which had a 10% chance of developing into mesothelioma.

Prichard said the decision could lead to statutory intervention, with the creation of a body like the Motor Insurers Bureau, passing the cost to the whole insurance industry.

It could also lead to claims being brought against the defendant with the "biggest pocket", leaving it up to the defendant to prove the claimant was exposed in several workplaces, he said.

Prichard added: "Initially, insurers might say this is a great decision but its not going to end here. It's going to result in more complex cases as claimants seek ways around it."

Unions and the Association of Personal Injury Lawyers (APIL) also criticised the decision

APIL president Frances McCarthy said it was an "absolute scandal" that employers and insurers had been "handed a loophole" that allowed them to escape accountability.

"How can it possibly be right that employers can get away with breathtaking negligence, which causes such a devastating illness to a man and his family?" she asked.

TUC health and safety spokesman George Brumwell said "careless and criminal employers" were the winners in the case.