The army is being forced to cap its growth because recruitment is unaffordable, a leaked Ministry of Defence document has disclosed. The briefing note entitled Controlling Growth in Army Strength is the first admission by defence officials that they do not have enough money to expand and provide further support to overstretched forces in Afghanistan. Senior army figures believe troop shortages are responsible for the growing number of British casualties in Helmand. Yet the Ministry of Defence concedes in the memo that increasing the size of the army beyond its full strength of 102,000 is too expensive. The document, sent out by army chiefs in July, said every 1% increase in size equal to an extra 1,020 service personnel would cost the army about 41m. If a recruitment cap is not introduced, the army will grow from its authorised limit of 102,000 to 104,500 by 2012.Unconstrained, such growth would have significant adverse structural effects, such as restricting promotion opportunities, the memo said. It is also unaffordable. Colonel Richard Kemp, former commander of British forces in Afghanistan, said: This may make sense to a budget manager, but it doesnt make sense to a military commander. We need more troops to dominate and keep the ground in Helmand and prevent further British casualties. The strength of the army should be determined by the need for combat troops. If we need more combat troops we should increase the size of the army, not go out of our way to curb it. Patrick Mercer, the Conservative MP for Newark, and a former army officer, said a cap in growth was effectively a cut because of growing casualty and sickness rates in combat units. Troop shortages and soldiers who are unfit for frontline duty mean virtually every infantry regiment is under strength by as much as 20%, or 140 soldiers, he said. Commanders on the ground say troop shortages have left them unable to hold territory taken from the Taliban, and unable to prevent the roadside bombings that have killed many British soldiers. In April, Gordon Brown refused pleas from military chiefs to commit 2,000 more soldiers to the region. An American troop surge was used to justify the decision. There are currently just over 9,000 British troops in Afghanistan, with 6,200 in Helmand, the scene of the fiercest battles with the Taliban. The overstretch in Afghanistan has already forced the army to break its own guidelines, which guarantee a two-year break between tours of duty in combat zones. Figures released earlier this year said 46% of all army units were in breach of the rule.