Through some conversations and a little research, I have found that there is an insurance product to insure against flood insurance policy excess. Yes, that's right - an insurance to cover the policy excess on flood insruance!
A £50,000 contents insurance with £5,000 excess, even with 2 claims in the last 5 years is coming up, with a CA13 postcode, of £243.
There are other brands and we/I are not recommending any brand or policy - the word is to talk to your broker. I found this link http://www.floodexcess.com that covers residentail properties. An enquiry showed that they do cover commercial properties but only via brokers.
Talk to your broker and find out more. This seems a possible route to help residents and businesses cope with the hikes in costs.