In its annual report on the Ministry of Defence's major equipment projects, the National Audit Office said overruns on the 16 biggest defence programmes meant costs had gone up during the past year by £468 million and, since they were approved, by £6.6 billion. Delays total 39 years.
The report disclosed that delays to the £32m Falcon communications system, which was developed for use in Afghanistan, meant it would not now be ready until after British troops have withdrawn in 2014.
Margaret Hodge, chairwoman of the Commons Public Accounts Committee which oversees the NAO, said: "Yet again, the MoD's annual report card has found unacceptable cost increases and delays."
Jim Murphy, Shadow Defence Secretary, said: "Less than a year after Philip Hammond (Defence Secretary) claimed to have balanced the budget, waste and delay are characteristics of his equipment programme."
Mr Hammond insisted "rigorous financial management" by the UK Government had reduced the annual cost growth of the biggest projects.