The police and prosecution service are "wasting" £55 million of taxpayers' money every year by mishandling court cases, an influential Commons watchdog has said.
Tens of thousands of cases are being unnecessarily delayed because of prosecution errors, such as losing files or not producing key evidence in time.
Edward Leigh, chairman of the Public Accounts Committee, said the scale of the problem was "alarming".
A report published by the committee on Thursday says that of around three million trials and pre-trial hearings in magistrates' courts in 2004-5, more than 900,000 did not go ahead as planned.
The cost of the delays is estimated at £173 million, of which £24 million could be attributed to the police and CPS individually, and a further £7 million jointly, according to the MPs.
Mr Leigh said: "The CPS and the police are jointly responsible for an alarming number of delayed and ineffective trials in magistrates' courts.
"This is not only a waste of taxpayers' money - some £55 million a year - but also an affront to society's expectation and demand that the guilty be swiftly brought to justice."
The Tory MP added that prosecutors needed to "cast a sharp eye" over the organisation's structure, and tackle "cultural resistance" to modern working practices.
"The management of cases must be radically improved, with fewer barriers between lawyers and administrative staff.
"There must be much better awareness of which cases are high risk so that evidence can be obtained in good time. The CPS needs to sharpen up its performance and start to emulate the most successful private law firms."
