I don't know how Clarkson's "Trust" is organised but certainly a significant element of trust to avoid IHT has been stopped by what I know as "the marginal benefit" rules (HMRC call it ‘gift with reservation’). Unless Clarkson has some way to avoid this, if his land is owned by a trust and he gains benefit from it eg using it to make TV programs or shooting on it or living on it, he has to declare the value of that benefit for personal income tax.I think I'd like to see them change the rules so that Clarkson can't use a Trust fund to avoid it. Ideally, so that nobody can, but I'd settle for just Clarkson not being allowed to, because he's an opportunistic nobber who publicly stated he bought a farm to dodge tax and now gets tetchy when interviewers point out that he's a leopard who ate some faces.
Confess: My parents took advice and placed their house into a Trust so us kids could inherit without IHT but a Rt Hon G Brown changed the rules and as they were living there rent free they had to start declaring rental value on their house as personal income and be income taxed on it. After a few years they decided to wind-up the trust and take back their house (it wasn't a particularly valuable house).
That said, for a farm I can see loopholes but doubt those would apply to Clarkson eg farmer is employed by the business to farm the land so he/she is not getting ‘gift with reservation’ but it's a job that may come with accommodation. But I'm no tax expert beyond my personal experience.
Ian