Insurers that underwrote asbestos mining in South Africa during the apartheid era could be liable for up to £50m in damages if the House of Lords grants an appeal by former mine workers.

The case between UK-based company Cape and a representative sample of more than 3,000 of its former South African workers, including 350 relatives, comes before the Law Lords on June 19.

The highest court in the land is being asked to decide whether the case should be heard in the UK, Cape's base, or South Africa where its asbestos mining took place between the 1940s and 70s.

The decision will be crucial because, if awarded, compensation payouts are generally higher in the UK than South Africa. The Court of Appeal which has agreed the appeal thought South Africa was the more appropriate jurisdiction.

Richard Meeran, solicitor for the mine workers. "Our contention is that Cape's South Africa operations were controlled from the UK and profits repatriated here," he said.

It is believed that Cape's asbestos mining activities were underwritten by a number of British insurers, although lawyers have been unable to confirm this. Representatives from several insurers have been present at earlier court proceedings but are not thought to have a direct interest in the case.