A confidential study into the educational standards of soldiers has revealed that half of all new infantry recruits only have the reading and writing skills of 11-year-olds.

The study commissioned by the Ministry of Defense, which the Telegraph has seen, also discloses that a fifth of recruits have the literacy and numeracy levels of seven-year-olds. Four per cent are at the standard of the average five-year-old.

Among the problems uncovered were one soldier who admitted that he struggled to write letters to his young daughter and another who wrote "riht" for write, "cepe" instead of keep, and "rifel" for rifle.

The findings have raised fears among defense chiefs that soldiers of the future may not be able to operate the new generation of "smart" weapon systems that will dictate how battles are fought. Officers, who are more highly qualified, were not included in the study.

Within the next 10 years, the Army will be issued with equipment that will require all frontline soldiers to be computer literate and numerically literate if they are to fight and survive on the battlefield. They will also need to be able to read and understand ever-more complicated training manuals.

By 2010, the Ministry of Defense plans to equip the Army with a new fleet of armored vehicles linked by a computer network and equipped with the most sophisticated weapons, communications and target-finding equipment available.

The £2 billion program will become a cornerstone of the Army and will be used by basic tank and infantry soldiers, who will require a high degree of computer literacy to operate it.

The study into the educational standards of recruits was based on the results of 2,000 basic skills assessments of new privates compiled by Melanie Dickinson, a civilian instructor at the Infantry Training Center in Catterick, North Yorkshire.

It reveals that four per cent of new recruits possessed a basic skill level equivalent to a five-year-old; 20 per cent equivalent to a seven-year-old; 50 per cent equivalent to an 11-year-old and 26 per cent had literacy levels equivalent to GCSE grades D to G in English and mathematics.

The reports states that there is a growing belief within the Army that believes that soldiers should be screened at recruiting centers for basic skills and those who are not up to an acceptable standard should be rejected.

Ms Dickinson admits, however, that this could create problems. "This could mean that the infantry would lose at least 25 per cent of its recruits in one go - and my own experience of 16 years in the Army tells me that you would also lose many good soldiers."

The report adds: "Nowadays there are very few soldiers who are entirely illiterate or innumerate, but there are a lot of soldiers who can't cope with the level of written information they are expected to understand."

The report goes on to say that the lowest educational level at which soldiers are accepted into the Army, called Basic Skills Level 1, is "widely accepted as the minimum level required to work and function in society in general".

No educational qualifications are necessary for privates seeking to join the Army, except for those who wish to train in technical trades such as signals, the Army Air Corps or the the various corps of engineers.

An applicant's suitability for a particular form of employment is determined by the results of an initial assessment, using computer touch-screen questions and answers.

A senior Army officer told the Telegraph: "Just because soldiers have literacy or numeracy issues, it does not mean they are stupid. Some of these individuals have very high IQs but they have been very poorly educated. There are soldiers serving in the SAS who struggle with reading and writing, yet they survive and become first-class soldiers, but they are the exception.

"The problem the Army faces is that the demands of modern military technology means that soldiers must possess more than the most basic of educational skills.

"In the very near future the basic infantryman will have to operate satellite navigation and target acquisition equipment in highly stressful conditions. If he can't read and write very well he will struggle to make the grade."