The Ministry of Defence has cancelled dozens of army training exercises to cut costs, it was claimed.
The Tories said the cuts, which have reportedly hit the regular as well as the Territorial Army, were compromising military capability.
But defence minister Bill Rammell condemned the criticism as "irresponsible scaremongering", insisting training courses were often rescheduled and all troops were prepared for the "challenges they face".
According to The Times, 56 exercises have been cancelled this year.
General Sir David Richards, Chief of the General Staff, told the newspaper: "Whilst in a perfect world we would have wished to keep options open for the various cancelled exercises, in practice the Army is now rightly focusing very much on defence's top priority - training for Afghanistan."
He admitted that troops would not have time between tours of duty to complete all the exercises on the programme and this could jeopardise core skills in the long term. Next year's Strategic Defence Review would need to resolve the problem, Sir David added.
Shadow defence secretary Liam Fox said: "It's clear that the Government is potentially compromising military capability to save money.
"Training isn't for fun. When we've got the Navy in the Gulf of Aden dealing with pirates and the Army and Marines in Afghanistan, we need to keep their military skills at the highest level of readiness.
"The Government must reassure the Armed Forces that these cuts will not have any impact on their readiness for current operations or to respond to the unexpected."
But Mr Rammell insisted: "This is irresponsible scaremongering without justification. Planned training courses have always been subject to cancellation or variation since the year dot. No service personnel would deploy to Afghanistan, our main priority, without adequate training."
