The Government was heavily criticised yesterday after deciding to keep secret a report into last summer's devastating power failure in London which brought chaos to the Tube system and cost business millions of pounds.
Stephen Timms, the Energy minister, said the investigation, carried out by the Department of Trade and Industry's engineering inspectorate, was not being made public because it contained "commercially sensitive" information.
Mr Timms also disclosed that none of the power companies involved in the London blackout last August, or a second power failure a week later in Birmingham, would be prosecuted. The companies concerned - National Grid Transco, EdF Energy, East Midlands Electricity and Aquila Networks - have been sent confidential copies of the report so they can act on its recommendations. But Mr Timms said the findings will not be made generally public because disclosure was restricted under the Utilities Act, 2000.
A spokesman for the London Chamber of Commerce said it was "unbelievable" that the investigation was being kept under wraps. "It is imperative this report is made public so we can understand and debate the reasons for this highly embarrassing power failure," he said.
"It was the worst possible advert for London, quite apart from the inconvenience it caused the public and the losses that business suffered. There is no reason why the report should not be made public so we can learn the lessons."
Stephen O'Brien, the Conservative's shadow Trade and Industry Secretary, also attacked the decision. "This is absolutely disgraceful. The public and business faced huge disruption and the fact that we are not being allowed to see the reasons behind the blackouts is astonishing. It begs the question of what the Government is trying to hide by suppressing this report."
Mr Timms said the DTI's engineering directorate would be holding discussions with the companies concerned and monitoring the action they took. If the recommendations were not followed, the DTI had the power to ensure compliance.
A report published last November by National Grid Transco blamed the London blackout on the faulty installation of a single fuse but insisted it was an isolated incident and not the result of a lack of investment or inadequate maintenance and operating procedures.
Since then, engineers working for the company have accused it of lax maintenance standards and allowing transmission equipment to remain in an unsatisfactory condition.
The energy regulator Ofgem is carrying out a separate investigation into the London and Birmingham blackouts and a subsequent power failure in Cheltenham and Gloucester to establish whether National Grid Transco or any of the other power companies involved had breached their statutory duties or licence conditions - offences which carry a fine of up to 10 per cent of turnover.
Ofgem is due to conclude its investigation in the next month and then pass the findings to the Gas and Electricity Markets Authority for a ruling.