I was listening to a farmer, who is not that ideological, who was running through the consequences this policy has for all farmers and it's pretty fecking brutal. It denies them, in many cases, the capacity to pass the farm on to their children. I.e., there's this thing where you need life insurance which many cannot get for certain farms to even have a prospect of being able to turn the farm over to the next generation. The fear is, and not without merit, that these will be bought up by capital hedgefunds and either rented back to the farmers at terribly expensive rates (enriching the already most rich) or broken up and sold.
I think it's a bad policy. Whilst farmers obviously own lots of land (70% of the UK's entire landmass apparently) these are not, typically, super rich people. And that, to me, is what an inheritance tax ought to be: a redistribution of wealth from billionaires not from farmers. I.e., billionaires to the state not farmers to hedge-funds.