Farmers protesting changes to inheritance tax should be “peaceful” and “passionate,” the head of the National Farmers’ Union said as he confirmed the demonstrations would “definitely” go ahead after “tough” talks with the Environment Secretary.

Tom Bradshaw said that some 1,800 members preparing to hold a mass lobby of MPs on Tuesday to fight the Government’s plans would leave an “indelible mark” in their campaign.

Thousands more are expected to join a separate rally in Whitehall as they protest against last month’s Budget, which also sped up the phase out of EU-era subsidies as funding is switched to nature-friendly farming schemes.

Mr Bradshaw met Environment Secretary Steve Reed on Monday amid sustained outrage among farmers about measures announced in the budget to impose inheritance tax on farms worth more than £1 million.

Speaking to the PA news agency in Parliament following the talks, he said that while there had been a “level of understanding” the protests planned for Tuesday are “definitely going ahead”.

“It was a valuable meeting. It was a great opportunity to really spell out in black and white why their evidence is wrong, why it has to come forwards in consultation, and what the extreme human pressure is that this policy has created.

“We have to have these conversations, but we’re really concerned that at the moment, there doesn’t seem to be any action. There doesn’t seem to be any understanding from the Treasury of what they’re doing.”

He added: “The whole focus was on this abhorrent policy that’s been put in place. We think it’s a very ill considered policy. I don’t believe that they intended the human consequences that there are within the policy they’ve put forwards.

“I don’t think they understand that family farms that are producing this country’s food are right in the eye of this storm.”

The union chief said he hoped that Mr Reed would “go away now and work with the Chancellor to try and get some sort of resolution” because the policy was “completely irrational” and “not well thought-through”.

“I genuinely feel there was a level of understanding, and, look, there were some really tough conversations,” he told PA.

Celebrities including TV presenter and farmer Jeremy Clarkson – who told the Times in 2021 that avoiding inheritance tax was “critical” in his decision to buy land – are expected to join the rally.

Asked what his message to farmers was, Mr Bradshaw told the PA news agency: “Be peaceful. Be passionate. We want the very best of the countryside to come to London to make sure that nobody can be in any doubt what this policy means for you, your family, your future.”

Speaking outside Parliament, he added: “I know that everyone is coming here to make sure the farming industry is shown in the very best light, that our true traditions from the countryside are brought to the city.

“And I’m sure that we will leave an indelible mark, but that it will be peaceful, and everyone here will understand what this means to farming across the UK.”

Organisers say they have no concerns over potential trouble despite speculation over far-right protesters attending.

Small farmers deserve all of our support – and they’re not helped by giving tax breaks to wealthy investors

While a procession to Parliament Square will be spearheaded by children on toy tractors, organisers have told those coming that they should not bring their farm machinery.

It is the largest show of anger to date over the inheritance tax changes for farming businesses, which limit the 100% relief for farms to only the first £1 million of combined agricultural and business property.

For anything above that, landowners will pay a 20% tax rate, rather than the standard 40% rate of inheritance tax (IHT) applied to other land and property.

Ahead of the protests, Mr Reed defended the changes as “fair and balanced”, saying it would only affect 500 estates a year and small family farms would not be hit.

Writing in the Daily Telegraph, Mr Reed said exemptions for agricultural land had led to wealthy individuals from non-farming backgrounds buying up land to avoid paying inheritance.

That had forced up rural land prices, “robbing young farmers of the dream of owning their own farm”.

And he said: “It’s become the most effective way for the super-rich to avoid paying their inheritance tax – and it’s costing other taxpayers a whopping £200 million.”

Speaking to reporters on his way to the G20 summit in Brazil, Sir Keir Starmer said it was important to support farmers, pointing to £5 billion over two years for farming in England, and said he was “absolutely confident the vast majority of farms and farmers will not be affected” by the tax changes.

Campaigner and author Guy Shrubsole has highlighted the inequality of land ownership in England, with 18% of land owned by corporations and a further 17% by oligarchs and bankers.

And he said data from the Environment Department (Defra) showed just 2,500 of the largest farms owned a quarter of England’s land, while 59% of farms were less than 50 hectares.

But farmers have pointed to other data from Defra which suggests 66% of farm businesses are worth more than the £1 million threshold at which inheritance tax will now need to be paid.

There's a complete disillusionment and distrust, and feeling of betrayal

Some have said the move could destroy UK food production, with family businesses in food processing and retailing, as well as farming, at risk from the changes.

Mr Bradshaw said he expected Tuesday’s events to be a “great demonstration of the very best traditions of the countryside”, with people being respectful but passionate, while Mr Harrison said he was not concerned about potential trouble from far-right groups at the rally.

A Met Police spokesperson said the force was “well prepared” for Tuesday’s protest and had had positive discussions with its organisers.

“We will have officers deployed in the vicinity to ensure the event takes place safely, lawfully and in a way that prevents serious disruption.”

The spokesperson added: “We are aware of speculation online that we have tried to ban tractors from the event.

“This isn’t true – we’ve policed protests involving tractors previously without any major issues and we have plans in place to do so again if required.”