As long as the vehicle is being used as soon as you take the policy out to come back to the UK, most UK insurers should have no issue with putting it on cover if you phone and explain the issue to them. The alternative is to insure the vehicle in France (this will provide EU cover), then drive it to the UK. Use www.gov.uk/importing-vehicles-into-the-uk and www.gov.uk/importing-vehicles-into-the-uk/register...e.

You will need to order the DVLA import pack, that will make much more sense to you. You will need proof of vehicle approval, but that should not be to much of an issue as the vehicle is already type approved in the UK.