The National Farmers' Union (NFU) is holding a mass lobby of MPs with 1,800 of its members - three times as many people as originally planned - to urge backbenchers to stand up to the Government's plans to impose inheritance tax on farms worth more than £1 million.
Many more joined 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.
Among the farmers and supporters was Jeremy Clarkson, who owns the Diddly Squat Farm in the Costswolds.
NFU president Tom Bradshaw gave a speech to members taking part in the mass lobby ahead of their meetings with MPs, at Church House, Westminster, in which he became emotional at moments as he highlighted the cost of the policy on farmers, as well as food security.
9. 'Back a farmer'
Farmers protest in central London over the changes to inheritance tax (IHT) rules in the recent budget which introduce new taxes on farms worth more than £1 million. Photo: Gareth Fuller
10. Children protesting
Children on toy tractors during a farmers protest in central London over the changes to inheritance tax (IHT) rules. Photo: Gareth Fuller
11. Farmers protest
Children on toy tractors during a farmers protest in central London over the changes to inheritance tax (IHT) rules in the recent budget which introduce new taxes on farms worth more than £1 million. Photo: Gareth Fuller