Almost £400,000 has been spent on proposals to flood one of Sussex's most popular beauty spots.

Environment minister Elliot Morley revealed the Environment Agency has spent £394,000 of £444,000 set aside for preparing its plan to flood all or part of the Cuckmere estuary near Seaford.

The idea has proved hugely controversial as the picturesque valley, visited by 350,000 people a year, would be reduced to marshland.

Campaigners last night called for a public inquiry to be set up before another penny is spent on the proposal.

Lewes MP Norman Baker, who obtained the agency's costs through a Parliamentary question, said: "I am extremely concerned to learn of the amount the Environment Agency has spent already on this controversial project ahead of any decision being made on exactly how they would implement their proposals.

"I am particularly concerned it has been allowed to go ahead and spend this proportion of their budget even though it has not yet agreed to the public enquiry their plans should generate.

"The Environment Agency must know by now their plans to allow the Cuckmere estuary to flood are hugely controversial, and expert opinion is split as to the need and desirability for this action.

"It needs to win public acceptance for its plan before more money is spent, and in my view the best way to deliver that is through a public inquiry."

The agency, which spends between £30,000 and £50,000 a year maintaining the area's flood defences, wants to abandon the Cuckmere estuary to the rising sea.

It said in November maintaining the defences, which will soon need to be replaced, was not worth the millions of pounds it would cost.

The agency sent out a consultation paper asking what local organisations thought it should do with the estuary, near the Seven Sisters cliffs.

If waters are allowed in, the area would return to marshland. The Environment Agency argues this is a more natural state and would be beneficial to wildlife.

There are three properties which overlook the estuary.

None would be harmed by the removal of defences but they would find the countryside around them transformed.

Landowner Nigel Newton, whose company Bloomsbury Books publishes the Harry Potter series, has submitted his own planning application to bolster defences by an extra metre and delay the flooding for an estimated 50 years.

Roger Frost, vice-chairman of Seaford Residents' Association said: "To spend this kind of money to seemingly defend the agency's position is absolutely ridiculous.

"It's amazing they should spend so much on this when they always plead a lack of money when asked to do what they are supposed to do. I don't see how this can possibly improve the situation. They're trying to save money but they are just throwing it away at the same time.

Rupert Clubb, Sussex area manager for the Environment Agency said the embankments would last another five to ten years and the £394,000 had funded extensive research over a number of years on possible options for a report to be completed in April.

The document will assess the economic, ecological and environmental aspects of maintaining the defences, doing nothing and allowing the banks to break, allowing the western half to flood and allowing flooding in the western half and part of the east.

He said: "It seems like a lot of money has been spent but the actual costs of maintaining the estuary as it is - which means coping with rising sea levels and recognising the embankments are starting to near the end of their lives - will cost £16 million.

"We need to make sure we spend our money wisely so we're spending a relatively small amount to find the right solution."

He said the public had been involved in various consultations and another would follow the report in April.