Heard good things about South Essex Insurance Brokers(if you are a member of British Horse Society they provide some of the benefits of membership, I have rang them before and they are very helpful)
The company I have used for years are NFU who are excellent reliable too.
OK ta, wondered as they were brokers rather than an insurance co. if you dealt with them for claims etc or another firm. Scouring the ads to get a cheaper quote now that NFU have upped their premiums heftily(not sure if thats a word!)