Running between New Cross Gate and Aldgate bus station, it is operated by Go-Ahead London.

When re-tendered, the route passed to Travel London's Walworth garage on 21 September 2005 with Wright Eclipse Gemini bodied Volvo B7TLs introduced.

[3][4] Abellio London successfully tendered to retain the route with a new contract commencing on 5 May 2011.

[6] Two additional morning peak journeys were introduced on 12 June 2010 with the intention of solving the problems; performance improved as a result, although the route continued to receive complaints.

[8] At 08:22 on 17 March 2012, a bus on route 343 caught fire on Pepys Road, New Cross.