The Commons public accounts committee has warned the Ministry of Defence that it must work more closely to ensure that costs of major procurement projects are brought under control.

The warning came in the wake of a £3 billion over-run in large projects last year alone.

The committee accuses the department of a poor decision in committing taxpayers' money to building a new class of nuclear-powered submarine.

The MoD and BAE Systems had "misunderstood the risks and costs", the MPs said.