The Government is being accused of "lunatic short-term thinking" after its calculations showed the food production land lost each year to the sea would generate far more money for the economy than it would cost to protect it.

As the Yorkshire Post revealed last year, the Environment Agency is to review every sea defence along the East Coast – and stop maintaining any that do not protect towns or are in areas of internationally-designated environmental importance.

It will perform a cost-benefit analysis for every inch of the coastline north of the Humber, but will rate all farmland as lowest priority without considering what is farmed or how much money is generated.

The Environment Agency said its hands had been tied by Government, which had instructed it not to factor the price of crops lost in its calculations. A spokesman said it "welcomed the debate" now being sparked.

Campaigners said that, under the Agency plans, 210 square miles of farmland will be lost to the sea in the coming years. At today's wheat prices, £153 per tonne, they calculate it will cost the economy £71.73m a year.

East Riding Council cabinet member for emergency planning Matthew Grove, a member of the Holderness Flood Defence Group, said the move was akin to the 18th century Highland Clearances, when Scots were forcibly moved out of the hills.

"We are talking about land that was reclaimed from the sea in the last century and is now some of Britain's best, most productive, farmland," he said. "The Environment Agency just want to give it back to the sea and wash their hands of the homes and live-lihoods of people who live there.

"There is a significant belief locally that they want farmland to be flooded to provide a wild-life habitat. That may not be correct, but it calls into question the level of consultation and education the Agency has undertaken if people still believe that.

"This whole area was dreadfully affected by the flooding of last summer, and some quest-ions remain over the Agency's decisions on flood defence invest-ment over a number of years. Now isn't the best of times to be making life and death decisions over local people in a cursory way."

Coun Grove said the Environment Agency consultation on its strategy, which took place earlier this year, had appeared to be "window dressing" rather than a genuine attempt to work policy around what people wanted.

He said farmers were telling the Agency that food shortages had "changed the mathematics" of allowing land to fall into the sea, but were being ignored.

Due to an increasingly affluent Far East, and producers' difficulties in meeting demand, global supplies of wheat have slipped to their lowest levels in 26 years. It has seen its biggest price rise in history, from £85 per tonne in April 2007 to tip the £200 mark around Christmas. This is being passed on to consumers with the average price of a loaf of bread 20 per cent higher than a year ago.

Coun Grove added: "This policy of losing farmland was first drawn up by the Government in the early years of this decade, during the era of set-aside, when farmers were encouraged to leave fields free to encourage wildlife.

"That era changed last year. The new agricultural reality is that we're now struggling to feed the world. To allow this fantastic area of high-quality, highly-productive farmland to disappear is extremely questionable. How much would that land cost to protect? Far less than will be lost through its disappearance."

The Agency said that while consultation on the strategy had finished, local residents and businesses would be consulted each time it came to stopping the maintenance of individual defences over the coming years.

Humber strategy manager Philip Winn said: "The Environment Agency must justify the way it spends public money on flood defences based on a range of social and economic factors set by the Government, including the number of properties and businesses that will be protected.

"The value of agricultural land is considered within this funding structure. As climate change bites and sea levels rise we anticipate it will be unsustainable to continue maintaining some defences on the Humber Estuary which protect flood plains that are very sparsely populated.

"But we welcome a debate of how different land uses are valued."