Train operators are warning of big delays and possible cancellations on services through Northamptonshire today (Friday June 5).
East Midlands Railway says a signalling fault between Luton and Bedford is affecting trains to Wellingborrough and Kettering.
Passengers could face delays of up to 30 minutes.
An EMR spokesman warned: "There is a fault with the signalling system between Bedford and Luton. This is disrupting our trains on the Sheffield / Nottingham / London St Pancras route.
Network Rail have teams on site investigating the fault.
"Trains running between Bedford and Luton, are being delayed in both directions up to 30 minutes, this will affect our trains heading into and out of London St Pancras.
"Some of our trains will be cancelled on our Sheffield / Nottingham and London St Pancras route to reduce the number of trains that need to go through the affected area.
"As soon as the problem is fixed our priority will be to get trains running to their advertised times again. At the moment we expect our advertised timetable to resume on the affected routes by 2pm."
A shuttle service is currently running between Corby and Kettering during the lockdown, but connections for passengers travelling to London, Nottingham or Sheffield will also be affected.
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