http://www.legislation.gov.uk/uksi/2004/257/contents/made
The Transport for London (Larcombe Close) Order 2004
Local Government
King's Printer of Acts of Parliament
2011-07-04
LONDON GOVERNMENT
TRANSPORT
Section 163 of the Greater London Authority Act 1999 prohibits Transport for London from disposing of operational land without the consent of the Secretary of State. Under section 164 of that Act, Transport for London is required to ensure that none of its subsidiaries does anything which Transport for London has no power to do (including anything which Transport for London has no power to do because the consent of the Secretary of State has not been obtained).