Flyingiraffe,
You may want to contact BALPA about this as well, first you'll need to become a member but don't worry : it's free as long as you're a wanabee and have at least a PPL . I know they work with an insurance company specialized for Seamen and Aviators and they do indeed have a Loss of Licence sort of scheme. At the time their prices seemed quite decent, around 40-50 quids a year to cover 20 grands if I do remember well.
Hope this help. SF