In the largest demonstration against the government's changes to inheritance tax laws to date, thousands of farmers from all over the United Kingdom are anticipated to assemble outside Downing Street today.

According to the changes included in last month's budget, farms valued at more than £1 million will be liable to 20% inheritance tax starting in April 2026.

Farmers say that will lead to land being sold to pay the tax bill, impact food security and the future of British farming.

The Government insists it is "committed" to the farming industry but has had to make "difficult decisions".

Farmers from Scotland, Northern Ireland, Wales and England will arrive in London to hear speeches from agricultural leaders.

Sky News understands TV presenter and farm owner Jeremy Clarkson, Conservative Party leader Kemi Badenoch and Lib Dem leader Ed Davey will also address crowds.

Protestors will then march around Parliament Square.

'It's really worrying'

"It's unfortunate, as Labour had originally said they would support farmers," said fourth-generation farmer Will Weaver, who is attending today's rally.

His 500-acre cow and sheep farm in South Gloucestershire has been in his family since 1939.

"We've probably buried our head in the sand a little bit. I think, back of a fag-packet rough estimates, tax is going to be north of half a million [pounds]."

The government is keen to stress that farmers will get a decade to pay the bill - but that comes as little comfort to Will: "It's more than our profit in any year that we've had in the last 10 years. Dad's saying we'll have to sell something. I don't know if we'll be able to raise that sort of money through a mortgage. It's really worrying."

As anger grows, there continues to be disagreement between the National Farmer's Union and the Government over how many farms will actually be impacted by the change.

The Treasury says only the wealthiest estates, around 500 of them, will have to pay under the new rules - claiming 72% of farms won't be impacted.

But farmers say that calculation is incorrect - citing that DEFRA's own figures show 66% of farms are valued at over £1m and that the government has undervalued many estates.

At the same time as the rally, the NFU is addressing 1,800 of its members in Westminster before they lobby MPs.