Thousands of commuters are facing "major" disruptions after London Waterloo, the UK's busiest train station, was hit by a signal failure on Monday 24 July.
Passengers have been urged to avoid the terminus and instead use their tickets on London buses, Southern Rail, Great Western Railway, Thameslink, London Overground and the London Underground, in a bid to get in and out of the capital.
"We are now working to introduce a few trains back into circulation around the network however, we continue to strongly advise you not to travel towards London Waterloo until after 09:00 [BST]," a South West Train spokesperson said.
The hub, which recorded almost 100 million journeys in 2015/2016, connects London to important stations in the south of England, including Bournemouth, Portsmouth, Exeter and Southampton. Waterloo is also one of the busiest transport hubs in Europe.
The signal failure comes just over a week before work starts to extend platforms at the station, with fewer South West Trains running to the travel hub between 5 and 28 August.
Mick Cash, the general secretary of the RMT Union, has used the incident to call for an end to cuts to Transport for London and Network Rail.
"The state of transport services right across London this morning serves as the clearest possible warning to this Government that their policy of hacking back the budgets of both Network Rail and Transport for London risks dragging tube and rail in the capital city into permanent chaos," he said.
"RMT salutes the engineers who are working flat out to get services back up and running this morning and we await detailed information. However, one thing is certain, if you cut back on budgets and the maintenance and renewals schedules you are storing up major problems for the future. That fact must not be ignored.
"This situation cannot go on. RMT has warned repeatedly that hacking back on maintenance and renewals leaves vital services on a knife edge. The Government should reverse their cuts programme and invest in the future while there is still time."