Southern, Thameslink, Great Northern and Gatwick Express trains may be subject to delays of up to 15 minutes this morning. Some may run at different times or be cancelled altogether.
All journeys on Southeastern are similarly held up.
Elizabeth line trains serving between Reading and Heathrow Airport have also been hit by the technical issue, according to National Rail. TfL currently displays ‘good service’ on the line.
ScotRail travellers can use their tickets for any other ‘reasonable route’ to get to where they need to go. The operator is recording ‘minor disruption’ on all 36 of its routes.
However, South Western Railway users can’t do so if they want to use their tickets to board a bus and should check Traveline to be on the safe side. Only a few SWR services have been impacted, with only major disruption to South Hampshire Locals.