A pensioner who says he was a "guinea pig" during atomic bomb tests in the 1950s is suing the Government.

Ex-serviceman Derek Connelly, of Churchill Road, Kidlington, says he was made to stand just wearing his shorts and socks to witness nuclear and hydrogen bombs being set off in the Pacific Ocean 50 years ago.

The 71-year-old's grandchildren have suffered miscarriages, deafness and premature birth, which he fears are linked to his exposure to radiation from the weapons.

Now he has joined forces with hundreds of other servicemen to sue the Government for damages.

The Government says it will argue in court that the legal action has been lodged too late.

Mr Connelly said: "We were taken out of our beds at about 2am just in our shorts and socks - no protective clothing whatsoever. We were made to stand with our backs to the blast, with fists clenched over our eyes.

"When the flash came, you could see every bone and sinew in your hand. The heat on your back felt like someone was running an electric fire across your body - and that was from 30 miles away.

"We didn't know much better. We were just all guinea pigs."

Four bombs were tested during the nine months he served on Christmas Island - now known as Kiribati - while serving in the RAF police, guarding airfields.

For three of the tests, Mr Connelly was 30 miles away from the blast, but for the fourth, he was just 12 miles away.

He left the RAF soon after to became a prison officer. He and his wife Jill moved to Kidlington in the 1970s. They have been married for 45 years and have five grandchildren.

Recently, Mr Connelly has suffered heart problems, while his grandson Ellis Connelly, now 18, was born prematurely, weighing just 1Ib 13oz.

His seven-year-old grand-daughter Freya Connelly-Warne was born deaf.

A third grandchildhe did not want to name has suffered three miscarriages.

Mr Connelly said there were no tests available to prove a link between the health problems and the nuclear bomb tests.

He said: "I never really thought about it until my children and their children started having health problems. I don't wish to achieve anything for me personally, but for my wife and family for after I've gone. But I'm also doing it for all those who have died since the tests.

"The Government needs to accept what happened. We have all been forgotten. It happened in 1958 and now here we are in 2008 and nothing has been done."

If the Government fails to persuade the courts to halt the ex-servicemen's case, it is expected to be heard in 2011.

A Ministry of Defence spokesman said: "When compensation claims are received, they are considered on the basis of whether or not the Ministry has a legal liability to pay compensation. Where there is a proven legal liability, compensation is paid."