Iza
Try HSBC ...they do a public liability/employers liability/legal expenses/treatment risk policy, with an excess of £250.
If you tell them youve been in business for 2 years, the premium is cheaper.
Premium is £246....and they are in bournemouth: Tel : 01202 455 545
Note: some companies charge in excess of £800 a year premiums!! I know which one I'd choose.