Ex-servicemen used as human guinea pigs in Ministry of Defence experiments at Porton Down have launched a bid for compensation.

Veterans who were subjected to chemical warfare agents experiments, from the 1940s to the 1980s, have instructed lawyers to seek compensation from the MoD for the injuries sustained as a result of the experiments.

Martyn Day, of Leigh Day & Co, said: "We hope that the MoD will deal with the claims swiftly and fairly out of court, if not, legal proceedings will be commenced in the High Court very shortly."

Among those seeking compensation is 75-year-old Geoffrey Thorne, of Birstall. The retired engineer was a 23-year-old RAF mechanic when he volunteered to take part in MoD trials at Porton Down in Wiltshire.

It was not until two years ago, at a second inquest into the death of Leading Aircraftsman Ronald Maddison, that he discovered he and hundreds of others had been exposed to the deadly nerve gas Sarin.

The inquest ruled 20-year-old Mr Maddison had been unlawfully killed.

Mr Thorne said he had mixed feelings about the likelihood of a successful case. "I am optimistic," he said.

"But not too optimistic because the MoD are very difficult people. What we really want is an acknowledgement that what they did was wrong."

"The MoD has never accepted what it did to us. It was a bad thing - that's what annoys me. A lot of people were told they were testing something for the common cold. We were not told anything as regards to what it was. I was deceived. I did not join up to be deceived like that and to put my life at risk."

Mr Thorne said two people had collapsed and their hearts had stopped at the Chemical Defence Establishment the week before he went to Porton Down, and Ronald Maddison died the week after.

Mr Thorne suffers from anaemia, poor immune system, a non-functioning spleen, chronic fatigue and has problems with his blood cells. He was forced to retire early from his engineering job because of poor health which he thinks could have been caused by exposure to the deadly nerve gas.

About 350 former servicemen who participated in the experiments have instructed law firms Leigh Day & Co and Thomson Snell & Passmore to seek compensation.

The veterans say they were not informed about the nature of the chemical warfare agents to which they were subjected.

Many believed that they were assisting in the quest to find a cure for the common cold and have only learned of the chemical agents to which they had actually been exposed in the last decade.

The veterans' legal team says a fifth of the group appear to have likely long-term adverse health consequences resulting from their exposures, ranging from long-term migraines, eye and nasal problems to nerve damage and psychiatric disorders.

Lawyers say the other veterans in the group sustained immediate adverse health effects, such as temporary blindness, severe migraines/headaches, inability to breathe, collapse and nightmares.

The group action will be served on the MoD at the end of this month.

e-mail: fiona.evans@bradford.newsquest.co.uk