[holding answer 3 July 2009]: The Security Industry Authority estimates that there are between 100 and 200 businesses in this sector.
[holding answer 3 July 2009]: The Home Office launched a public consultation on 30 April 2009 on proposals for regulation of vehicle immobilisation businesses. The consultation document can be found at:
http://www.homeoffice.gov.uk/documents/cons-2009-vehicle-immobilisation/
Many local authorities employ contractors to carry out enforcement of on-street parking regulations but they do not in that context regulate the businesses themselves.