Victims of asbestos-related cancer today won a High Court battle against insurance companies who were trying to block compensation pay-outs.

The decision means that people who contract the lethal disease mesothelioma decades after being exposed to the deadly dust will continue to have access to damages.

It was hailed in the West as "hugely significant victory" for the many people in the region - and their families – who either have either died from or are expected to fall victim to the incurable condition in the future.

For years insurers have paid damages – often running into six figures – to victims of the fatal lung disease on the basis that their liability arose at the time when a worker was exposed to asbestos dust.

But two years ago after action by four insurance giants, the Court of Appeal ruled that liability was "triggered" when the disease actually developed - sometimes after 40 years or more - rather than at the time of exposure.

As a result, insurers stopped paying on a "time of exposure" basis and argued that they were not liable because the risk cover they provided 40 years ago was no longer in force.

This summer, the legal battle continued over nine weeks when six test cases were brought before London's High Court in the form of families fighting for compensation after losing members to the disease.

Yesterday the judge Mr Justice Burton ruled in favour of the test cases which means that employees can claim against the employers' historic insurers - even though there is no exact proof of when life-threatening tumours develop.

He said: "For the purposes of these policies, injury is sustained when it is caused and disease is contracted when it is caused."

Last night specialist lawyer Brigitte Chandler, of Swindon based Charles Lucas & Marshall said: "This is a hugely significant victory for victims of asbestos-related disease and their families.

"If the High Court had ruled that the policy in place at the time of the diagnosis was the relevant one it would have made it more difficult to claim compensation."

For decades, right up until the Eighties, asbestos was used to lag pipes in factories, ships, locomotives and even buildings such as hospitals until its full danger was finally acknowledged.

Ms Chandler said that as a result of its wide use asbestos related disease was now the biggest cause of work-related death in the UK, mainly affecting railway-workers, construction workers and other heavy industries.

In Swindon mesothelioma is known as the Swindon Cancer because so many former employees at the town's railway works had succumbed to it, usually decades after initial expose.

Ms Chandler, who founded the Swindon and South West Asbestos Victims Support Group said: "The majority of companies which employed workers who go on to develop the disease are no longer in business.

"This made it vitally important for workers to have access to compensation through employers' liability insurance.

"This decision today enables that and that's why it is no important."