A survey of rail companies has found less than half of people travelling in the West Country are satisfied with the service they get.
The findings by Which? put South West Trains and First Great Western almost bottom of the list of train companies in the entire country.
55% of commuters said they were dissatisfied with the service they received.
Alex Neill is Head of Campaigns at Which?...
There's major disruption on the trains this morning between Bridgwater and Taunton, and Taunton and Plymouth/Penzance.
Meanwhile, trains from the West Country into London are also subject to delays.
First Great Western said it would only be able to run four trains an hour between Reading and London Paddington because of flooding near Maidenhead.
South West Trains is operating a heavily-curtailed service.
South West Trains has announced that there will be no services running on any route before 7.30am on Christmas Eve because of the bad weather.
Trains on some of the country's busiest routes were cancelled or delayed tonight because of emergency 'heat related' engineering work, causing disruption for thousands of passengers.
South West Trains services to and from London Waterloo were hit at the height of the evening rush hour, on one of the hottest days of the year. The disruption was caused by emergency engineering work and signalling problems near Haslemere in Surrey.
Rail passengers commuting between London and the West Country have suffered major disruption this afternoon. A defect has been identified with a section of track outside Waterloo Station. Trains to and from Yeovil and Exeter are starting and finishing at Basingstoke.
South West Trains advise passengers to use First Great Western services from Paddington where tickets are being accepted. They can also check the latest updates by following @SW_Trains on Twitter.
Find out more here.
Heat-related emergency engineering work is being carried out on a track defect, discovered at Waterloo Station earlier this afternoon. As a result, four platforms at Waterloo are not currently in use. There will be disruption to services for the rest of the day.
Trains between London Waterloo and Dorking are cancelled. Customers should travel on Southern services between London Victoria and Dorking. A train shuttle service is in operation between Hampton Court and Surbiton. Passengers will need to change trains at Surbiton.
Services that run from London Waterloo at 50 minutes past each hour to Salisbury / Yeovil Junction / Gillingham are not running between Waterloo and Basingstoke.
Customers travelling from London Waterloo / Woking will need to change trains at Basingstoke or travel on services to Exeter St Davids departing London Waterloo at 20 minutes past each hour. Some services heading towards Waterloo may be cancelled to ease congestion.
There are delays on trains out of Waterloo because of problems with railway lines during the heatwave. Emergency engineering works are needed near platforms 1-4 at London Waterloo to resolve a rail defect.
South West Trains says normal service has resumed between
- Yeovil Junction and London Waterloo
- Exeter St Davids and London Waterloo
- Salisbury and London Waterloo
It follows earlier over-running engineering work at Wimbledon
Disruption on South West Trains between Waterloo and Yeovil Junction, Exeter St Davids and Salisbury due to emergency engineering works at Wimbledon - they are not running between Basingstoke and Waterloo. This is now likely to continue until 1pm.
Tickets are being accepted on CrossCountry, First Great Western, Southern, London Underground and London Bus services.