Many services have been canceled and trains still cannot run between stations.
The signaling issue between Kings Cross and New Barnet was first reported at 5 a.m. this morning (September 7).
Great Northern said: “Please DO NOT travel this morning if you are using Kings Cross to Peterborough / Cambridge services.
“We have implemented a number of ticket acceptances if your travel is essential. ”
Follow the latest updates on rail delays between Cambridge and Peterborough and London Kings Cross below: