Four council officers are facing disciplinary proceedings over a bus scheme that spiralled £6 million over budget.

West Sussex County Council has been strongly criticised by an independent inquiry into why Crawley's Fastway bus system is going to cost £28.7million rather than the original £23 million.

The scheme, due to be completed next financial year, serves Crawley, Gatwick and Horley.

It gives buses priority at key junctions, has bus lanes and provides electronic passenger information.

An audit carried out by East Sussex County Council found that there had been a pattern of "ineffective accountability, complacency, ineffective risk management and a lack of clear ownership of the financial management responsibilities."

It said officers had failed to report to councillors what was going on and too much responsibility was placed with officers who did not have the necessary skills.

The report said there was still confusion about the financial position.

According to West Sussex County Council, the latest estimate is that the overspend will be £5.7 million, less than the £6.2 million estimated in July.

The money will come from funds earmarked for other major projects.

Councillor Tex Pemberton, West Sussex Cabinet member for highways and transport, said in a letter to councillors: "It is clear that the quality and reliability of the financial and project management have been unacceptable."

Conservative Coun Pemberton said disciplinaryprocedures have been started against four officers who may face action if they cannot provide explanations for their failures.

Councillors will have an opportunity to ask questions about the report at the next full council meeting on December 16.

Morwen Millson, a Liberal Democrat councillor on the policy and resources committee, said: "The Conservatives regularly proclaim their financial competence at election time. They seem to have left the financial management of this multi-million project in the hands of a highways engineer and a trainee accountant.

"The Cabinet doesn't appear to have been asking the searching questions it should have been."

Coun Pemberton said the overspend should not detract from the "overall success" of the scheme.

He said: "Fastway is meeting its original objectives, and more. Passenger numbers are 40 per cent above those predicted and the service has won national and international recognition.

"Despite increased construction costs, it is delivering value for money and I am confident it will continue playing a major role in attracting people to use buses instead of cars.

"The council is to follow up recommendations in the report to review and consider overhauling the way it handles major projects."

The council may pursue utility companies for some of the additional costs caused by delays in work. It said some other costs were caused by inflation in the building industry.

The council has stressed there will be no direct increase in council tax to pay for the overspend.

Coun Pemberton said: "We will not be abandoning any other projects. In a big programme, there are always schemes than cannot go ahead on time and we are constantly moving finance between schemes."

The auditor's report is available at www.westsussex.gov.uk