Stick in a google search, just type in; Public liability insurance "uk"
Then take your pick

And good god, £3000 for public liability

Don't you mean employers liability, or is there some reason that means it is that high?
For 2 million pounds worth of cover, public liability that is, on UK mainland you should be paying somewhere between £80.00 and £150.00.
It really isn't that expensive.
Employers liability is a different story altogether of course

Regards,
Ian