Rail passengers travelling along the East Coast Main Line have been warned to expect disruption due to a shortage of train staff, with at least 16 services cancelled.
London North Eastern Railway (LNER) said the cancelled trains included various services running between Edinburgh and London, passing through stations including Newcastle, Darlington, Durham and York.
Several other LNER connections are expected to be delayed or have their routes changed.
The disruption is also affecting passengers elsewhere in the country, travelling on the Chiltern Railway and Great Western Railway.