The Conservative chairman of the Commons Business and Enterprise Select Committee is pressing for an overhaul of the way that government-commissioned independent inquiries are conducted as the investigation into the collapse of MG Rover will tomorrow begin its fourth year.

Peter Luff said: “There is a clear need to look at the process of government inquiries because the delay to this one has become unacceptable now.”

The investigation into the demise of Rover, which itself existed for only five years, has so far cost £12.2million and there is no end in sight. It has yet to produce an interim report to the Department for Business, Enterprise and Regulatory Reform, to which it will eventually issue a full account.

The investigators, who are led by Guy Newey, QC, have also clocked up nearly £438,000 in expenses during their inquiry into the collapse of the Longbridge-based independent carmarker.

Mr Luff said that the investigators, which include forensic accountants from BDO Stoy Hayward, should “at least produce an interim report to show some progress”.

Under the existing rules, ministers cannot set a time limit on independent inquiries, nor give them specific instructions. However, there has been concern on a number of occasions over the length of time that investigations take and the amount of public money they cost.

The MG Rover investigation was begun by Alan Johnson, then Trade Secretary, in the wake of the collapse of the company. MG Rover folded after partnership talks with Shanghai Automotive Company failed and suppliers to the business began to withhold goods because they had not been paid.

There had been longstanding concern from politicians, unions and some businesses in the supply chain over the running of the company by the Phoenix Four consortium of local businessmen.

John Towers, the chairman, and his associates had taken over the company from BMW for £10 on a wave of local emotion and gratitude that Rover had been saved. But suspicions about the conduct of the directors mounted when they established a labyrinthine corporate structure and took out large amounts of money as dividends. The investigation is seeking to establish if the directors acted properly and to find the causes of the company's failure.

Richard Burden, Labour MP for Northfield, which includes Longbridge, is also angry at the delay to the report. “It is taking a ridiculous amount of time. I don't know how long it took to write War and Peace but it probably didn't take as long as this,” he said. “There is now a wall of silence from the inspectors. The last letter I wrote to them was just bounced on to the Department for Business.”

Mr Burden said that local people needed a report to be produced so they could put the issue to rest.

A spokeswoman for the Department for Business said: “The investigation is continuing. We are in regular contact with the inspectors and they are aiming to complete as quickly as possible.”

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