TRAINS between Havant and Portsmouth or Fareham are delayed by up to two hours until further notice.
The major delays are being caused by electrical problems at Havant.
South West Trains services from Portsmouth Harbour to London Waterloo are being diverted via Eastleigh, and replacement buses are running between Havant and Guildford.
Buses are also running between Portsmouth Harbour and Havant.
Services between Fareham and Southampton are reduced and South West Trains passengers can use Southern services between Havant and Fareham.
Anyone with tickets for South West Trains and Southern services can use local buses between Portsmouth Harbour and Havant.
Passengers with First Great Western tickets can use First Hampshire and Dorset buses on routes 17, 18, 41, and Portsmouth Hard Interchange to Portsmouth and Southsea and routes 1, 1A, and 5 Portsmouth and Southsea to Fareham.
Southern passengers can use local buses, route 700, between Chichester and Havant.
A spokesman for the South West Trains/Network Rail Alliance said: ‘We apologise for the current disruption to our services.
‘This is due to an electrical supply problem affecting the line between Havant and Portsmouth Harbour.
‘Engineers are currently on site working hard to rectify the problem to allow us to get back to normal as soon as possible.
‘A revised timetable will be in place until further notice which may result in cancellations or some extended journey times.
‘Customers are advised to check in advance of travel for updates at southwesttrains.co.uk or follow @SW_Trains on Twitter.’
Routes effected include London Waterloo, Guildford, Haslemere, Havant, Bedhampton, Hilsea, Portsmouth and Southsea, and Portsmouth Harbour, also Brighton, Worthing, Barnham, Havant, Cosham, Fareham and Southampton Central. Passengers are advised to use the National Rail Enquiries real-time Journey Planner online at nationalrail.co.uk to find out the impact on their journey and get alternative travel options, or call TrainTracker on 0871 200 4950.