The head of the Army has issued a warning to ministers that any further cuts to spending would jeopardise the success of the service's reform programme.
General Sir Peter Wall, the Chief of the General Staff, said they would need all their current allocation if they were to deliver a "well-trained, well-equipped and fully funded" force capable of defending the national interest.
His intervention comes after the former chief of the defence staff, General Lord Richards of Herstmonceux, warned last night that the armed forces were not in a fit state to deal with the current threats facing the country - most notably terrorism - and would deteriorate further if spending did not increase.
And earlier this month, the National Audit Office warned of "significant risks" to the Army reform programme - known as Army 2020 - which is seeing the regular Army cut by 20,000 to 82,000 while the number of part-time reservists is being increased from 19,000 to 30,000.
Speaking at the Royal United Services Institute land warfare conference in London, Gen Wall said that any further cuts in next year's strategic defence and security review could leave them unable to honour commitments made by Defence Secretary Philip Hammond.
"This is primarily about resources. The complexity of our change programme and its dependencies is significant - with plenty of risk," he said.
"We will need all of our current resource allocation - and the freedom to reinvest savings in equipment support - if we are to deliver Army 2020 in a balanced manner and realise Mr Hammond's commitment to a firm foundation of men and materiel, well trained, well equipped and fully funded to operate in the nation's interests.
"In particular, any pressure on our equipment programme is likely to lead to an unbalanced force."
With operations winding down in Afghanistan, Gen Wall acknowledged that there was currently little appetite among politicians for fresh military engagements overseas.
"Boots on the ground may be out of vogue in the run up to a UK election - certainly in a combat context," he said.
However he stressed that it was vital that the Army was prepared to deal with any new threat which might emerge.
"We must pay special attention to understanding the rapidly shifting environment in which we may well have to operate sooner than some would have us think," he said.
"Demand for land power may well be low at this point in the cycle - more from public reticence than because the world lacks security challenges - but that could soon change."