Hundreds of people are being prosecuted for refusing to complete the 2011 census because of its links to an arms manufacturer, campaign group Count Me Out has said.

Up to 400 are being chased up for not taking part in the nationwide survey, which the group said was believed to be due to Lockheed Martin being used as a technical consultant by the Office for National Statistics (ONS).

It said 120 people have already been found guilty, a huge increase on the last census in 2001, when only 38 people were prosecuted.

Count Me Out spokeswoman Kat Hobbs said: "Ten times more prosecutions than the last census shows that people are really angry about the involvement of an arms company.

"The Office of National Statistics can no longer deny that giving the census contract to Lockheed Martin was a mistake when so many people are being prosecuted as a result of it."

She said one of those to be taken to court is conscientious objector John Voysey, 82.

He said: "The same reason why I registered as a conscientious objector in 1947 means that I cannot do the census if an arms company is involved. My objection to the arms trade is a deeply held religious belief and leaves me with no choice but to break the law.

"It is an outrage that Lockheed Martin was given the census contract and so many people were forced to choose between their conscience and breaking the law."

An ONS spokesman said: "There are always a number of people who, for whatever reason, fail to fill in their census. If there is evidence that they are wilfully refusing then a prosecution may take place. It is technically a crime."

He said Lockheed Martin had also been involved in the 2001 census, but a spokesman for Count Me Out said that there was less publicity about it then.

Press Association, photo by Images_of_Money