http://www.legislation.gov.uk/ukpga/1999/29/section/155Greater London Authority Act 1999An Act to establish and make provision about the Greater London Authority, the Mayor of London and the London Assembly; to make provision in relation to London borough councils and the Common Council of the City of London with respect to matters consequential on the establishment of the Greater London Authority; to make provision with respect to the functions of other local authorities and statutory bodies exercising functions in Greater London; to make provision about transport and road traffic in and around Greater London; to make provision about policing in Greater London and to make an adjustment of the metropolitan police district; and for connected purposes.1999-11-23texttext/xmlenStatute Law Database2026-01-09Expert Participation2026-01-01 Greater London Authority Act 1999s. 334(2A)-(2E)Levelling-up and Regeneration Act 2023s. 95(2)s. 247s. 255(3)(b)Greater London Authority Act 1999s. 334(9)-(11)Levelling-up and Regeneration Act 2023s. 95(3)s. 247s. 255(3)(b)Greater London Authority Act 1999s. 337(1A)Levelling-up and Regeneration Act 2023s. 96(1)(c)s. 96(4) 247s. 255(3)(b)Greater London Authority Act 1999Sch. 23 para. 1(3A)Levelling-up and Regeneration Act 2023s. 244(2)s. 247s. 255(9)(a)Greater London Authority Act 1999Sch. 23 para. 3A 3B and cross-headingLevelling-up and Regeneration Act 2023s. 244(3)s. 247s. 255(9)(a)Greater London Authority Act 1999Sch. 23 para. 4(2A)(2B)Levelling-up and Regeneration Act 2023s. 244(4)s. 247s. 255(9)(a)Greater London Authority Act 1999Sch. 23 para. 4A and cross-headingLevelling-up and Regeneration Act 2023s. 244(6)s. 247s. 255(9)(a)Greater London Authority Act 1999s. 337(2)(ca)Levelling-up and Regeneration Act 2023Sch. 6 para. 15s. 247s. 255(3)(b)Greater London Authority Act 1999Pt. 4 Ch. 8ABus Services Act 2025s. 29s. 41(5)Greater London Authority Act 1999s. 334(2A)(b)Planning and Infrastructure Act 2025s. 58(2)(a)s. 116s. 118(2)(g)Greater London Authority Act 1999s. 334(2D)(b)Planning and Infrastructure Act 2025s. 58(2)(b)s. 116s. 118(2)(g) Part IVChapter II1551The Mayor may issue to Transport for London—aguidance as to the manner in which it is to exercise its functions,bgeneral directions as to the manner in which it is to exercise its functions, orcspecific directions as to the exercise of its functions.2Directions issued by the Mayor under subsection (1)(c) above may include a direction not to exercise a power specified in the direction.3The guidance or directions which may be issued by the Mayor under subsection (1) above may include in particular guidance or directions as to the manner in which Transport for London—ais to perform any of its duties, orbis to conduct any legal proceedings.4Any guidance or directions issued under subsection (1) must be issued in writing and notified to such officer of Transport for London as it may from time to time nominate to the Mayor for the purpose.S. 155(1) applied (with modifications) (temp.) (3.7.2000) by S.I. 2000/1504, arts. 4, 9(1)S. 155(1) restricted (22.7.2008) by Crossrail Act 2008 (c. 18), s. 38(2)