The number of farms that could be affected by the change in agricultural property relief (APR) on inheritance tax is disputed.
The government says it will only 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 could be affected in total.
Secretary of State Steve Reed told the that Labour was “on the side of rural Britain”.
He added: “I completely understand that with any change comes a degree of uncertainty but if farmers look at the facts, they will see that the vast majority of farms will be unaffected by this.
“The figures are very clear – and they’ve been endorsed by the independent Office for Budget Responsibility – and they show that no more than 500 estates will be affected.
“The vast majority of claimants will pay nothing under the new scheme just as they pay nothing under the old scheme.”
The government has also said that combining tax reliefs and exemptions, depending on individual circumstances, could actually allow up to £3m to be passed on free of inheritance tax.
It added that any inheritance tax bill could be paid in instalments over a 10-year period.
A group from the Royal Agricultural University’s students’ union were also set to join the rally.
Student Alaw Jones, who is the ninth generation of her family to farm livestock in west Wales, said her parents had always planned to hand down the business to her and her sister but now “all the work they have done to build the business and get this farm to stand on its own just feels like it’s for nothing.”
She added: “Mental health is a massive issue in the agricultural industry and this feels like the final nail in the coffin for those farmers who are already struggling.”
Rupert Dale’s family run a hay farm on the Worcestershire/Shropshire border supplying livestock farmers across the country.
He said the family now fear they will have to sell up, explaining: “Me and my brother would have to pay an immense sum for our farm to carry on and that’s a sum that we spoke about together as a family that we would not be able to finance and afford.”
Students’ union president Alexandra Godfrey said: “I think this is one of the most pressing challenges in the farming sector and we all need to rally together to tell the government how we feel. If not now, when?”
