The army's major operational exercise in the Gulf last year was dogged by numerous equipment failures, according to a National Audit Office report out today.

The investigation, which raises serious doubts about the army's ability to participate in a land assault on Iraq, reports that in addition to engines becoming clogged with dust after a few hours, other equipment, from guns to boots, also failed to hold up to operating in the desert.

While uniforms proved to be to hot, helicopters also struggled in the dust and heat, the report says.

A Ministry of Defence spokesman said: "We have made comprehensive arrangements for identifying lessons and, where necessary, we will make improvements to our equipment and our procedures."

The exercise, codenamed Swift Sword, was the largest deployment of British forces since the Gulf War of 1991, and involved more than 22,500 personnel.

Conservative defence spokesman, Bernard Jenkin, said the report showed "the need to re-learn the lessons we forgot in the 10 years since the Gulf War".

The Sun today reports that retired frigates HMS Boxer and HMS Brave are to be used in a test of missiles and torpedoes.