I'm very concerned about this - if you disclosed the accident when applying for the insurance, their criteria would have flagged up straight away as to whether you were acceptable or not - there must be something more to it than that.
Without meaning to sound funny, was that previous accident in any way ''dodgy'', because if it was, then your husband will be loaded on every conceiveable database we have, and you won't get insurance again.
Let me know what the insurer's come back to you with as a non-fault accident shouldn't really make a difference to be honest.
Do you have any disclosed convictions on your licence? I'm really confused as to why they have taken this line of action as insurers have strict underwriting criteria they have to adhere to when taking on new business. The only reason we would refuse the insurance like this is if something came up after the policy had been taken out.