The result of the Portobello inquiry into plans for a giant sewage treatment works at Telscombe Cliffs is scheduled for December.

The 150-page report by Simon Gibbs of the Planning Inspectorate into Southern Water's £60 million scheme for works on the beach has been delivered to the Environment Department.

Ministers are now studying the findings.

Mr Gibbs heard 44 witnesses give evidence over 43 days between October and February at the inquiry in the Meridian Centre, Peacehaven.

He also assessed scores of written documents and letters.

The details of the report are being kept secret and there will be no announcement on the contents until every section has been assessed.

The final decision will probably rest with Deputy Prime Minister and Environment Secretary John Prescott. But it is thought the groundwork will be prepared by his junior minister Nick Raynsford.

A spokeswoman for the Central Office of Information said: "We expect to make an announcement in December.

"We aim to take a maximum of 13 weeks between the receipt of the inspector's report and the Government's decision.

"Portobello is such a complex issue, the final decision is expected to take the maximum amount of time."

The inquiry was prompted by East Sussex County Council's rejection of the scheme, which followed massive public protests.

Southern Water says it looked at 44 sites before deciding on Telscombe Cliffs.

The water giant needs to build a new plant for the Brighton area to comply with European clean water regulations and says Telscombe Cliffs is the best option.