An insurance broker can give you a wide choice of insurer and can also give you professional advice and help in selecting the right type of cover for you. Many brokers now have web sites where you can input your requirements and their online system will present a list of quotes for you. If your requirements are in some way out of the ordinary then the broker approach is the most likely one to unearth a good quote.
A direct insurer will claim to be cheaper because they cut out the middle man. but you are limited to just the products from that one company or you have to spend some time filling in a variety of online forms. When they first started up, you could buy your cover cheaper, obtain it faster and obtain better service both at the point of sale and at the claim stage. From where I sit, on straight forward cases I have to say that I think this is still true.
A holiday claim by a Sussex man relates how he was "rushed to the
medical centre for two injections, two stitches, antibiotics and
anti-tetanus powders" following this: "Savaged by fish - finger bitten
(almost off)".
Extracts taken from actual claim forms submitted to
a number of UK home insurance companies
A mortgage provider will try and insist that you buy their products. In general, I would advise against this. You will almost certainly be better off searching the market and buying your cover elsewhere. Your mortgage provide legally owns the building and can obviously dictate to you about your buildings cover. You most certainly must buy adequate buildings cover but find a mortgage supplier that will allow you to choose your buildings insurer (even if you have to pay them a fee).