Historic buildings dating from centuries back are likely to be lost to the sea.

A bid to have tank traps and pill boxes at Cuckmere Haven listed will not stop plans to flood the valley and turn it into mudflats, Environment Agency officials have insisted.

The agency has completed a three-month public consultation on the plan and will make a final decision will be made in June.

The preferred option is to stop maintaining existing defences, allowing the area to return to a tidal estuary.

When that happens acres of flood plain will be lost and revert to mudflats.

Within a decade the headland coastguard cottages will be lost to the sea as a result of erosion.

Historic wartime artefacts will also disappear if the valley becomes tidal.

Alan Edgar, of campaign group Plan Sussex, wants to construct a tourism trail through the valley to attract visitors to nearby Seaford which he said was "dying on its feet".

He said: "The Cuckmere Valley is really a chronicle of history over the years. It was a decoy for Newhaven during the war and was lit at night so it would be bombed instead of the port.

"Then there are the tank traps and pill boxes and going farther back in history, to Napoleon the Third's time, the canal through the valley was constructed to get barges up to Alfriston and military personnel up to the Cuckmere Haven garrison.

"Going even farther back you have the coastguard cottages built just after the turn of the 18th Century to guard against smuggling.

"People like that history so it's our intention to put together the walking trail and the listing is part of that.

"We're trying to get what's important listed - starting with the tank traps. The dragon's tooth ones on the east side are particularly rare."

Mr Edgar has already secured the support of Seaford Town Council for his listing application to the Department for Culture Media and Sport and is waiting to hear from Cuckmere Valley Parish Council and East Sussex County Council.

But an Environment Agency spokesman said: "It is not within our duties to protect heritage even when listed.

"The known cultural heritage and potential for buried archaeology was assessed as part of our strategy work. Some of these could be damaged as the area changes and others could benefit from a more stable wet environment as they became buried in the estuary system.

"We are not in a position, or required under our duties, to preserve or mitigate against natural changes that result from our recommendation."

In a desperate bid to preserve the structures Mr Edgar has applied to Lewes and Wealden District Councils to raise the banks by one foot which would preserve the area for an additional 50 years. However, no funding has been secured for the work.

Mr Edgar added: "Returning the valley to a tidal estuary will certainly flood some of the artefacts we are talking about and could well destroy valuable archaeological remains."

But an Environment Agency spokesman said: "We can't spend flood risk money on protecting a flood plain when there are communities out there we need to protect."

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