Council leaders have defended spending millions of pounds of taxpayers' cash to pay specialist consultants, including a bill of �3.3m to get expert advice on the proposed incinerator in King's Lynn.

Over the past three years, councils in Norfolk and Suffolk have racked up a bill of more than �13m to employ external experts, a Freedom of Information request has revealed.

Norfolk County Council was the biggest spender on consultants, having spent just under �5.6m in the financial years 2009/10, 2010/11 and 2011/12.

Of that sum, just over �3.3m was spent seeking advice over its waste contract plans, which resulted in plans for an incinerator at Saddlebow.

The county council says that plant, which would be built and run by Anglo-US Consortium Cory Wheelabrator, is vital to deal with the county's waste.

Former environment secretary Caroline Spelman had agreed to hand over �91m in waste credits to the council, so the company can deal with 170,000 tonnes of the county council's waste for the next 25 years, which council leaders say will save millions of pounds of taxpayers' cash.

But 65,000 people said no to incineration in a poll organised by West Norfolk Council and critics say other alternatives to incineration should be used.

The Freedom of Information request has revealed exactly where the money which the county council spent seeking advice on the PFI contract went.

Professional services firm Ernst & Young was paid just under �1.95m in three instalments for financial advice on the contract, while legal advice from solicitors Sharpe Pritchard cost just over �736,000.

The county council also paid environmental consultants Enviros a little over �645,000 for their expert advice and about �21,000 to insurance firm Marsh Ltd for risk and insurance consultancy.

Tim East, Liberal Democrat spokesman for environment, waste and transport at the county council, questioned why the council could not use its own experts.

He said: 'In this economic climate, where they have cut something like 1,600 jobs and are saving �135m, why are they spending so much money on external consultants.

'They still have a wealth of experience and expertise there, not least at nplaw [a shared legal team formed through a merger of the legal teams from Great Yarmouth Borough Council, Norfolk County Council and Norwich City Council].

'It seems incredible that the council is spending so much of its money on consultants when they are cutting front line services.'

But the Conservative administration at County Hall defended the spending, saying it added up to best value for money in the long run.

Harry Humphrey, cabinet member for finance and performance at Norfolk County Council, said: 'Any large organisation, and Norfolk County Council has an annual spend in the region of �1.5bn on a wide range of services, will need particular specialist advice from time to time.

'This is to ensure the authority runs as efficiently as possible, takes decisions based upon the best available advice and information, and obtains the best value for money.

'Over the last three years spending on consultants has declined sharply. This reflects the tight grip we are keeping on our spending and proves we are ensuring we are best use of limited resources in these difficult times.

'We only seek external specialist advice when we do not have the right expertise within the council.

'It is not surprising that we have needed specialist legal services and other advice to take forward The Willows energy from waste proposal.

'This is a highly complex project that has reached a crucial stage, but the cost of this advice is a fraction of the �8m a year saving for council tax payers if the plant goes ahead.'

The second biggest spender in Norfolk was Norwich City Council, with more than �1.4m spent over the three year period.

An example is �16,500 paid to Sector Treasury Services to help the council's finance team. But the council said such spending helped the authority be confident that its borrowings and investments obtain the best return possible while eliminating or minimising risk.

Alan Waters, cabinet member for resources, said: 'We use consultants only where necessary to obtain expert advice or to deal with particular issues where it would not be practical or sensible for us to employ specialist staff.

'The council has rigorous value for money criteria that must be met before any consultants are taken on, and follows procurement processes designed to ensure the right mix of quality and price is obtained.

'We're confident that our controlled use of consultants represents the best possible value for Norwich's council tax payers.'