Steve,
There are a couple of things that you can do if you've
had an accident with an uninsured driver:
1) You can contact your local Citizen Advice Bureau and ask for advice
2) You can call a solicitor specialising in motoring laws and explain the circumstances of the accident and get feedback on what you can do next
3) If you've had injuries from the accident, you can claim through the Motor Insurer's Bureau (MIB) (no repairs to your vehicle but personal injury compensation)