From June 2011 a new scheme is being introduced to make sure that all vehicles are insured and recorded on the Motor Insurers Database (MID) unless a Statutory Off Road Notification (SORN) has been made.
All registered vehicle keepers must ensure that their vehicle has at least the statutory minimum third party motor insurance - failure to comply could result in a fine (fixed penalty notice), wheel clamping or court prosecution. You can check whether your vehicle is recorded on the MID at www.askmid.com
This means that you must carry a motor insurance policy on your vehicle even if you have taken it off the road because you are not using it for whatever reason unless you have SORN'd the vehicle with DVLA.
More information is available on the DVLA website: