Passengers on the some of the UK's busiest rail networks are set to benefit from new carriages, longer and more frequent trains and a greater choice of destinations.
The upgrades come as a result of new franchising agreements between the Department for Transport and operating companies Southeastern, First Capital Connect and Southern Railways.
The changes are part of the £5.5bn Thameslink modernisation programme set to be completed in 2015.
Passengers will see: an increase in frequency of trains from eight to 15 running through central London at peak hours, a new fleet of trains with extra carriages providing 14,500 extra seats and more direct journeys.
Station improvements will take place at Blackfriars, Farringdon and London Bridge stations to increase capacity and ease bottlenecks.
Platform extensions will also take place at 50 stations outside central London.
Rail Minister Tom Harris MP said that the department is committed to improving the experience for passengers travelling on Thameslink.
"The changes will deliver a dramatic increase in capacity for passengers in London and the South East," he said.
By Daniel Garrun
