Unions have reacted angrily to a ruling that will prevent workers claiming compensation for an asbestos-related condition.

The law lords ended a 20-year right to compensation for pleural plaques, a scarring of the lungs, by ruling it was not a disease.

The decision came after a four-day hearing in June. The law lords were acting on an appeal by Amicus – now part of Unite – against an earlier ruling by the Court of Appeal in January 2006.

Derek Simpson, joint general secretary of Unite, said: “The judgment will disadvantage many of our members who have been exposed to asbestos.”

Alan Ritchie, Ucatt general secretary, said: “This is a disgraceful decision. Businesses knew the risks but decided to play fast and lose with lives. The courts are letting them get away with their recklessness.”