Emergency services are dealing with an incident between London Paddington and Heathrow Airport / Reading.
The incident means that all lines are currently blocked, with trains either being cancelled / revised or being delayed by up to 55 minutes.
Disruption is expected for trains between London Paddington and Didcot Parkway / Oxford / Hereford Cheltenham Spa / Worcester Shrub Hill / Cardiff Central / Swansea / Bedwyn / Bristol Temple Meads / Taunton / Plymouth / Paignton / Newquay / Penzance until around 12 noon.
Ticket acceptance is in place with other operators, please see National Rail Enquiries for the latest travel advice.
