Rail passengers faced disruption on the Portsmouth-London line today.
South West Trains said a signalling fault had caused delays, cancellations and diversions between Havant and Guildford.
A spokesman said: ‘A major signalling power supply issue yesterday evening affected a large number of our services until the end of service last night, particularly between Guildford and Haslemere. Train services on this route continue to be disrupted by this issue and may be cancelled, delayed by up to 60 mins or diverted via Eastleigh. Disruption is expected until 5pm
‘Our engineers are still working to resolve these ongoing issues, and have identified the fault. To fix the fault, they need to block the line between Haslemere and Havant for approximately 3 hours from 11:45.
‘Our services will be diverted to run non stop between Fratton, Hilsea and Woking via Eastleigh in both directions. Stopping services between Haslemere and Waterloo, and between Portsmouth and Waterloo will run normally in both directions.
‘A replacement bus service will run between Guildford / Haslemere and Havant.
‘Southern Railway will accept South West Trains ticket holders for travel between Clapham Junction and Havant / Portsmouth Harbour in both directions.
Great Western Railway will accept South West Trains ticket holders for travel between Guildford & Redhill / Gatwick Airport to connect to Southern services to & from Portsmouth Harbour.
‘If you hold a South West Train tickets you can use Stagecoach Bus routes 700 and 23 between Portsmouth and Havant.
‘We’re very sorry for the disruption this has caused to your journey, both yesterday and today.’