Richard Alexander: here to gather evidence

The inspection, by lawyers for the group and an occupational health expert, is looking at parts of the factory where staff say they were exposed to poisonous chemicals.

A separate investigation by the Health and Safety Executive is already looking at allegations that the cancer rate among workers at the plant, which opened in the early 1970s, is higher than the national average.

The company denies there is scientific evidence to support the allegations and says it is committed to providing a safe working environment.

About 70 workers lodged a class action against National Semiconductor at a court in Santa Clara, California, where the company is based.

Attorney Richard Alexander said: "We made application through the court in California for the visit to take place and National Semiconductor agreed to grant us this facility at their Greenock plant which will play a vital part in the evidence gathering.

Grace Morrison blames her cancer on chemicals

"We have obtained plans of the factory, although these are only recent.

"Former workers will be able to try and describe exactly what processes they worked on in which areas."

Former employee, Grace Morrison, who blames her cancer on chemicals used in the plant, said: "Bringing this case in the American courts will be a major step in bringing the electronics industry to account for its lack of concern for the welfare of its employees."