Waterloo disruption on London Marathon day
Major engineering work at Waterloo Station could disrupt some people going to the London Marathon on Sunday.
A limited service will run on routes to and from Waterloo until 16:00 BST while a track crossing is fixed. Replacement buses will be provided.
The work was scheduled for last weekend but was postponed due to a problem with equipment supplied by contractors.
A spokesperson for South West Trains said: "It is vital this work is carried out as quickly as possible."
"Until the defect is repaired, there is a real chance it could fail," the spokesperson added.
The work will put platforms 1 to 10 at London Waterloo out of use.
'Risk to infrastructure'
Jake Kelly, customer service director for South West Trains, said: "Sunday is the only opportunity we have to carry out such major work.
"Even if the work could be delayed until the following weekend - which it can't because of the real risk of the infrastructure failing - it would impact a sell-out rugby semi-final at Twickenham.
"It is also impossible to carry out this work between Monday and Friday - around 300,000 people use Waterloo station in both the morning and evening peaks each day."
Despite the number of passengers expected for the London Marathon, South West Trains says Sunday will still be less busy than a normal weekday.
Replacement buses will be supplied, and tickets will be accepted on First Great Western, Southern, London Underground and London Overground routes.
South West Trains is advising marathon participants and spectators to check the latest information before they travel and allow extra time for their journey.