- Watch Mike Pearse's report below
Engineering work that will close part of the Brighton line for nine days gets underway this weekend.
The line will be closed between Three Bridges and Brighton and Three Bridges and Lewes.
It is expected to cause chaos for commuters while work is done to improve the line.
A fleet of 250 buses will be laid on in the biggest bus replacement operation in the country.
This section of the Brighton line will then reopen on Monday 25th February, however some work may continue across several weekends up to May.
There will be trains from Brighton, and other stations to the west, to and from London, but these will be diverted via Littlehampton and Horsham.
There will be no direct trains to London from Lewes or Eastbourne.
- How will my journey be affected? Click here to find out.
The engineering work is part of a £300 million government-funded programme to tackle delay hotspots and hopes to boost reliability of the railway in the south east, including the expanded Thameslink network.
Network Rail says this section of railway is 'responsible for more delays to Southern, Gatwick Express and Thameslink passengers than any other'.
- Tips when travelling
- check your timetable to see which trains will serve both your home station and your destination
- plan ahead and consider these dates when booking leave
- work from home if possible
- travel outside the busiest times and allow more time to travel
- non folding bicycles will not be carried on the replacement buses.