The Crown Court in England and Wales is at "breaking point" after a 5 per cent rise in cases to 136,000 a year, an independent watchdog has found.

As a result there are delays of several months in the hearing of serious criminal trials and the congestion is so bad that the Courts Service, the agency in charge, is spending millions of pounds converting magistrates' courts to tackle the backlog.

Meanwhile, only 70 per cent of cases last year were committed for trial within 16 weeks of coming before the magistrates and the Courts Service missed its target of dealing with 78 per cent of cases within 26 weeks. Delays are worst in London and the South East.

The findings by the National Audit Office were put this week to Chris Mayer, chief executive of the Courts Service, when she came before the Commons Public Accounts Committee. Edward Leigh, its chairman, who has described the system as "almost at breaking point", condemned the delays and "time-wasting" as "scandalous", adding: "Is this really a dysfunctional organisation? Can you run it properly?"

Many cases committed for trial were not complicated, he added, and should be brought on more quickly than they were. For good measure he also attacked the agency over court closures and over the obsolete, 20-year-old computer system that runs the management of cases. The agency cannot afford to replace it and is instead spending another £10 million updating it.

Meyer made her defence as best she could. She pointed out that there were no plans for further court closures; that the computer system was a good one, despite being 20 years old; and that the particularly long delays in London and the South East in part reflected the heavier cases heard in that area, such as terrorist trials in Woolwich and the most complex cases at the Old Bailey.

The courts' problems come at a bad time. It costs £380 million to run the 500 courtrooms at almost 100 locations throughout England and Wales. The Courts Service plans to spend £120 million to increase numbers of Crown Court rooms by 30, or 6 per cent, over the next three years. Yet it is working to a tight budget and within the Ministry of Justice that faces a £90 million-shortfall in its income for courts generally because of a deficit in income derived from fees paid by court users.

How much of this budget shortfall will hit the criminal courts is not known. Ministers are sensitive about the cuts to the courts system and, along with Mayer, are declining to give interviews.

Dominic Grieve, the shadow justice secretary, said: "Labour has consistently undermined criminal justice over the past 12 years, closing around seven courts each year. This has done lasting damage to British justice."

The Conservatives have identified that 150 magistrates' courts have closed since 1997 but only 70 new ones been opened. A Courts Service spokesman said that only seven of the closures had occurred since the agency was set up in April 2005, taking over responsibility for closures from local magistrates' courts' committees.

At the same time, cases are being increasingly diverted from the courts. Grieve added: "Criminals don't get the punishments they deserve but are let off with a glorified parking ticket or slap on the wrist. Meanwhile, innocent people have been robbed of basic judicial protections. This is the worst of all worlds - neither firm nor fair."

Beyond the criminal courts, the Law Society Gazette has reported delays in the opening of the proposed business court: the original date of 2010 has now become "on track for delivery in 2011".

The new court, under construction in Rolls Building in Fetter Lane, close to the Royal Courts of Justice, is to replace the commercial and other courts working from the cramped St Dunstan's House nearby. The aim is to ensure that London does not lose its place as the prime centre for commercial dispute resolution.

A Courts Service press officer insisted that 2010 was set before work began. "The exact completion date of any large and complex building project is always uncertain," he said. "Further guidance will be given as to the likely opening date but we are confident that this will be in 2011."

With the public sector facing its toughest cash constraints for years, it is no surprise that the courts cannot escape some of the impact. But ministers cannot pretend all in the legal garden is rosy; nor that victims, witnesses and those bringing or defending civil claims will not suffer.

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