Save British Farming founder Liz Webster said: “This government has unleashed a really nasty culture war with their budget.
“Are they hoping to motivate envy to back destruction of our farms which produce healthy and sustainable food and care for our countryside to sign a deal with Trump which delivers chlorinated chicken and hormone-fed beef?”
A government spokesperson said its reform to Agricultural and Business Property Relief would impact about 500 estates a year.
“For these estates, inheritance tax will be at half the rate paid by others, with 10 years to pay the liability back interest free. This is a fair and balanced approach which fixes the public services we all rely on,” they said.
National Farmers’ Union (NFU) president Tom Bradshaw said the organisation was not involved the protest, but it supported it.
Thousands of people also protested in London last week over the changes.
The prime minister previously said he understood farmers’ concerns, but added “the vast majority” would be unaffected.
Government research suggests that an average farm last year made a profit of about £45,300 – although that figure may be overstated as it is based on a survey that excluded farms that bring in the least money.
The government says it will affect the wealthiest 500 estates each year, but the NFU and the Country Land and Business Association (CLA) have estimated up to 70,000 farms worth more than £1m could be affected.
Between 2021 and 2022, 117 farms with a value of more than £2.5m were inherited.
