The Chiclot report has strongly ciriticised the ministry of defence for its failure to provide British forces occupying Iraq with adequate protection.
The MoD was "slow" to respond to the threat from Improvised Explosive Devices (IEDs) and provide better armoured vehicles, the report found.
The report stated: "The MoD was slow in responding to the developing threat in Iraq from improvised explosive devices."
Following the release of the report, the criticism was picked up by David Cameron in parliament, who called the situation "unacceptable".
Among his criticisms invasion of Iraq, Sir John Chilcot laid into delays in providing troops with an additional type of Protected Patrol Vehicle (PPV).
The PPV was not ordered until 2006, after ministerial intervention, even though request for the vehicle began "before 2002".
Instead troops were expected to use the light "snatch Land Rover", a decision that has been much criticised by the families of those killed in the conflict.
Soldiers reportedly nicknamed the vehicles "mobile coffins" because of the limited protection they offered from IEDs and the families of several of those killed are suing the MoD over their use.
The report also criticised a lack of helicopter support and equipment for what is known as Istar - intelligence, surveillance, target acquisition and reconnaissance.
The report did not identify any department or individual responsible for the equipment gaps, but said that such delays "should not have been tolerated".