There's disruption on First Great Western services between Bristol Temple Meads and London Paddington and between Cheltenham Spa and London Paddington due to a person being hit by a train between Swindon and Didcot Parkway.
Trains may be delayed by up to an hour, and buses have been requested to run between Swindon and Reading.
Tickets are being accepted on CrossCountry and Virgin Trains services.
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Stephen Gilbert who was the constituency's MP from 2010-15 will contest the St Austell & Newquay seat for the Liberal Democrats on 8 June.
It'll be dry and sunny to begin with this Bank Holiday weekend in the West, but with showers just around the corner.
It's a mixed weekend for the South West ahead with sunshine on Saturday but rain and showers across Sunday and Monday.