Hi,
Not had to deal with this problem myself, but i just done a quick search and found these insurance companies.

http://www.freedominsure.co.uk/
http://www.orbisinsurance.co.uk/trav...onditions.aspx
http://www.allcleartravel.co.uk

Also have you tried to talk to the Citizens Advice Bureau? Maybe they could help you.
http://www.citizensadvice.org.uk/

Good luck
rainbow74