A leading councillor has accused two councils of complacency over controversial plans to build a waste incinerator.

Brighton and Hove City Council and East Sussex County Council agreed the business case for waste plans costing £1 billion over the next 25 years at a meeting last week.

The document must be approved by the Department for Environment, Food and Rural Affairs to secure Government credits for the private finance initiative deal.

The £100 million of credits will help towards the capital cost of building an incinerator, proposed at North Quay, Newhaven, and other infrastructure projects.

David Rogers, Liberal Democrat opposition leader at the county council, said the report had been "nodded" through at a confidential meeting of senior councillors.

He said councillors and officials refused to answer questions about how much of the deal's financial risk would be carried by the two councils and how much by preferred bidder Onyx Aurora.

He said: "I was horrified by this level of complacency about a billion pound contract, affecting every household in the city and county.

"It could well be that council taxpayers will not only have to pay more for waste disposal but also be saddled with the uncosted risks.

"If the proposed incinerator goes ahead, many people are worried about long-term health effects and about who would be liable."

The councils said the Government credits would help offset the costs of the contract and the rising costs of waste disposal.

County council environment councillor Tony Reid said the report had not been nodded through and the contractor would be responsible for a lot of the financial risk.

He said: "There was not a huge debate. The reason being that members of the two councils have been following this on a weekly basis.

"We feel the contractor shoulders a lot of the risk. Our team is working hard to get the fairest and most practical balance of the risk."

Coun Reid said agreeing the business case did not mean the councils would automatically approve the contract terms being negotiated.

The councils are expected to meet next month to approve the finalised contract.