Rebuilding work at the station could mean disruption and inconvenience to passengers for over a year. Those travelling to London Bridge using Southeastern's Charing Cross service will need to take another route entirely from today.
The service won't get back to normal until August 2016. Platforms one through six will be closed for works as part of Thameslink's £6.5bn programme to relieve congestion.
Simon Blanchflower, Network Rail's Thameslink programme director, said:
We realise this will mean big changes to some people's journeys and we have worked with operators across the industry, including Transport for London, to make sure people can plan their new journeys and get to their destinations without extra cost.
Which routes are affected?
The Jubilee line at London Bridge, and other stations including Blackfriars, Cannon Street, Charing Cross, Embankment, Elephant and Castle, Southwark, Victoria and Waterloo are likely to be busier than usual thanks to diverted National Rail passengers.
Parts of the London Overground network, especially Canada Water, Brockley and New Cross, the DLR and some bus services are also likely to be busier.
London Bridge Underground station will operate as normal throughout all the work.
Southeastern services from New Cross, St. Johns, Deptford, Greenwich, Maze Hill and Westcombe Park stations will no longer operate to and from London Charing Cross or Waterloo East.
No Bedford to Brighton Thameslink trains will call at London Bridge station until January 2018.
Network Rail's response
To deal with the disruption to passengers, more staff are being deployed, as well as more services on the bus network. Route 21 between London Bridge to Lewisham via New Cross will get ten more double-decker buses at peak times in the evening.
Route 47 between London Bridge and Lewisham will also receive 10 extra buses. TfL said Network Rail passengers who have a London Terminals season ticket may need to update it.
Last week, London Bridge played host to chaotic scenes as hundreds of commuters queued for trains that were delayed for up to half an hour. A host of others were cancelled. The Department of Transport and the London Assembly's transport committee demanded explanations for the disruptions last week.