Hi Pete,
I've just received a public liability quote from the NFU this week.
They are a no quibble pay out firm that stand by their customers and the fact you can actually go into your local branch and speak to an actual person!
I've had it tailored to suit my place and situation as I wanted a non standard product.
It covers me for me working on other farms, as well as my 50 sheep, tools, rented buildings, etc, etc and gives me loss of earnings cover as well as goods in transit etc.
It works out at £535/year compare that to public liability ins that you need to work self employed on others farms at £465 it makes the extra £70 for the cover seem good value!
The only down side is that the sheep trailer isn't insured but can be added onto my car policy if I renew with the NFU.