Great Western Railway (GWR) is warning of severe disruptions and no long-distance services across its network today due to Aslef union's strike action.

This action will disrupt other railways including Chiltern Railways and CrossCountry on May 8.

A downscaled, revised timetable will be implemented for the affected operators with limited service duration.

Notably, various parts of the GWR network won’t be operational.

A truly limited service will operate on several GWR routes between 7am and approximately 7pm.

These include Reading to Oxford, Reading to Basingstoke, Reading to Newbury, Westbury to Swindon (at peak times only), Cardiff to Bristol, Exeter St Davids to Barnstaple, and Penzance/St Erth to St Ives between 9.30am to 12.30pm and 3.30pm to 7pm.

In addition to the strikes, the GWR network, especially the London Paddington to Reading route, will be affected by engineering works.

Furthermore, customers are warned of potential disruption due to industrial action from May 6 to May 11 which may result in short-notice alterations and cancellations.

Post-strike days may also witness short-notice cancellations.

Customers planning to travel where trains are functional are advised to check both outward and return journeys before setting off.

Running trains will be exceptionally busy, and replacement bus services will not be supplied.

Customers who purchased tickets but are unable to travel can claim a full refund or modify their ticket.

Also, those who are delayed by 15 minutes or more may be eligible for Delay Repay compensation.

GWR is allowing tickets for the strike days to be valid for travel on or before Monday, May 13.