The conflict in Iraq left a third of Britain's armed forces less prepared for action than they should have been, an influential group of MPs has warned.
Mr Ingram said the report did not reflect the current state of UK forces
The Public Accounts Committee found major operations in Iraq and elsewhere had produced "worrying signs of strain" in the military.
Troops had to "cannibalise" equipment from material left at home to keep units up to strength, the MPs said.
But defence minister Adam Ingram said he did not agree with the findings.
The PAC report said there were concerns that the priority placed on re-equipping the RAF and Army may have hit the Royal Navy's capabilities.
Over the year up until September 2005, around 30% of the UK's armed forces had "serious" or "critical" weaknesses to their peacetime readiness levels, the MPs said.
Edward Leigh, the committee's Conservative chairman, said: "This reflects the high levels of demands being put on them, and there are worrying signs of strain on equipment.
"I am particularly concerned about the potential impact on future operational capabilities of the fleet.
"The Ministry of Defence needs to make clear its plans for bringing the armed forces up to readiness."
'Long term effects'
Military forces are kept at varying levels of preparedness to respond to emerging operations, so they can deploy from anything between a few hours to several months.
But the committee warned that "continuing high levels of operational commitment" were leading to "significant strain on equipment support in particular areas, with long term effects".
During operations in Iraq, 44 Challenger 2 Main Battle Tanks - 22% of those not deployed to the conflict - were "cannibalised", the report said.
However, Mr Ingram insisted that the PAC report did not reflect the current state of British forces.
He argued that the conclusions were at odds with a positive National Audit Office report.
"Recent operations prove we can deploy the right number of forces to achieve our objectives," he said.
"The National Audit Office was absolutely clear that the MoD has a good system for reporting the readiness of the armed forces and has a good understanding of the risks to readiness and good plans to mitigate them.
"The impact of current operations on the armed forces is judged by the chiefs of staff to be manageable and the armed forces as a whole remain ready for future operations."
Richard Bacon, a Conservative member of the committee, said 30% of the armed forces equated to 60,000 servicemen and women who were not at the right level of readiness.
"The Ministry of Defence must discharge its duty as to ensure British forces are properly trained and equipped to deploy," he said.
Cannibalisation of equipment "decreases the pool of available vehicles and equipment and increases the wear and tear they are subjected to, shortening their useful life", he added.