It sank quietly more than a decade ago, after an outcry from conservationists.

But could a tidal barrier across part of The Wash be back on the agenda?

The Environment Agency admits such a structure might one day be needed to protect King's Lynn after calls from climate change activists in the town.

"Going back a hundred years, there's been the idea of a tidal barrier on the Great Ouse and indeed across The Wash," the EA said.

"Currently the tidal defences along the Great Ouse provide a high standard of flood protection to local communities and in recent years we have done improvement works to defences within King's Lynn.

"At the moment there are no plans to look at a barrier, but when we start to look longer term at flood planning for the Great Ouse, of which we have just started looking at the Fens, we expect some form of barrier will be one of the options that will be considered."

Plans for a barrage were proposed in 2008, when the Wash Tidal Barrier Corporation said it wanted to build an 11-mile-long structure between Skegness and Hunstanton.

It said it would protect the up to 500,000 people and 300,000 hectares of land, along with generating green energy from the tides.

But the RSPB and other conservation groups attacked the plan, saying it would damage an internationally-important estuary for birds.

No plan is currently in place. But the EA added: "As explored through recent public consultation on the draft National Flood and Coastal Erosion Risk Management Strategy, climate change and the need to adapt to sea level rise will mean that flood resilience and infrastructure choices for communities along our coast and estuaries need to be looked at over a long term timeframe."

A flood defence barrier is already being constructed acrosss The Wash from Lynn in Boston.

The Environment Agency says the structure, across the River Witham. It will protect more than 14,000 homes when it is completed in December.

Some 300 homes in the Lincolnshire fishing port were flooded during the storm surge of December 5, 2013.