An emergency timetable has been put into place after major disruption on rail services from Hertfordshire, Cambridgeshire and Norfolk into London's King's Cross.
Urgent engineering work is taking place in the Alexandra Palace area of north London.
First Capital Connect is operating an amended timetable. It affects services to and from places like King's Lynn, Ely, Cambridge, Peterborough, Stevenage, Letchworth and Royston.
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Showers becoming heavy this afternoon, with thunder possible.
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