Labour has been accused of plotting the “slow death” of thousands of traditional English farms to meet environmental targets.
The Government wants farmers to shift away from food production towards measures like solar panels and tree planting.
Its eco-plans could mean the equivalent of 12,000 farms closing within a generation, according to Tory analysis.
Farmers have slammed the move as an “attack on Britain’s rural identity” which threatens the nation’s food security.
About 9% of England’s farming land will need to be converted into forest and wild habitats by 2050 to meet the Government’s net zero and nature targets.
Former environment secretary Steve Barclay said: “Before the last election, I warned that Labour’s eco plans would force thousands of farmers out of business – and the Government’s own documents now show this was correct.
“Labour’s published plans would force the equivalent of 12,000 farm businesses to close within a generation – and the reality could be even worse.
“This is in stark contrast to my focus as Secretary of State on better supporting food production, aligning nature schemes with improvements to soil quality and farm productivity so that food production and nature went hand in hand.”
The Government, which is consulting on its plans, insisted not all farms will close and some will just change the use of part of their land.
But its own figures, released alongside its consultation on a Land Use Framework last week, showed thousands of farmers will be encouraged to move away from their food production businesses.
The Government said 760,000 hectares of land will be subject to “category four” land use change by 2050.
This describes a shift away from agricultural land to being fully dedicated to delivering environmental and climate benefits.
Figures from the Department for Environment, Food and Rural Affairs have found the average size of a UK farm was 81 hectares, meaning that an equivalent of 9,383 average UK farms will be subject to this complete shift away from food production.
A further 430,000 hectares would be subject to “category 3.2” land use change, which would only include “limited food production”.
Estimates by Mr Barclay, who conducted the analysis, suggested this will remove at least a further 219,300 hectares from food production – the equivalent of another 2,707 average UK farms. This is based on the “most generous assumption” of 51%.
It means to meet Labour’s targets, the equivalent of 12,000 UK farms will need to shut down the way they operate and switch by 2050.
James Wright, farmers and policy director at the Conservative Rural Forum, said: “Not content with the family farm tax, Labour’s Land Use Framework is a blueprint for the slow death of British farming.
“The Government’s figures admit they want to encourage up to 12,000 farms to turn their backs on food production. This risks turning our countryside into a carbon offset scheme for corporations while jeopardising our food security.
“This isn’t just an attack on farmers, it’s an attack on Britain’s rural identity, our economy, and the families who feed the nation.”
Farmers have told the Express they fear the Government has heaped inheritance tax on farmers in a bid to force them to sell and use the land for net zero targets.
The Daily Express has demanded that the Government U-turn on this through the Save Britain’s Family Farms crusade.
YouTub farmer Olly Harrison called the tax raid “morally short sighted”.
He said: “What do they [the government] think we’re going to eat? Every day people need to eat so importing it from another country just adds more climate footprint. It’s bonkers.
“We’ve asked for conversations to discuss it with them but they just seem to be [ignoring us]. There’s no conversation. It’s morally short-sighted.”
The fourth generation farmer, 43, previously told the Express he could be forced to sell some of the farm when he inherits it from his 76-year-old father Thomas to pay tax bills.
Chancellor Rachel Reeves placed a 20% inheritance tax on farmers’ assets worth more than £1 million in her October Budget from April next year.
Farmer Andrew Ward, who helped organise London protests last year, said: “I bet everyone who voted for Labour is now realising that they voted to live under a dictatorship because that’s virtually what this country has become.The only good thing, possibly, might be that the Labour Party won’t last more than their first term of government so hopefully none of these things will actually take place but it’s ludicrous to say taking land out of production won’t affect food security.
“We need to import less, not more. It’s crazy to think that on the one hand they say we need to take land out of producing food to look after the environment more and then they go and announce a third runway for Heathrow Airport. You just couldn’t write it. They really don’t’ know what they’re doing and the sooner they’re out of Government, the better.”
Tim Bonner, chief executive of the Countryside Alliance, said: “A land use framework is an important step forward in determining how we go forward for farming, nature and net zero. This should not, however, be about partitioning up the countryside but ensuring that we deliver all requirements together in the most effective way. The future is farming and nature, not farming or nature”.
A government spokesman said: “This is absolute nonsense.
“The Land Use Framework will not tell anyone what to do with their land. Instead, we will publish the most sophisticated land use data ever published to empower farmers to boost their profits and make the most out of their land.”