Network Rail has issued a statement apologising to Great Northern and Thameslink passengers for issues with this morning’s train service, as disruption is set to continue until midday.

The rail company has cited overrunning engineering works among one of the problems causing delays of up to an hour and cancellations today.

Major improvement works saw no trains running into London King's Cross over the weekend.

A Network Rail spokeswoman said: "We're really sorry for the disruption which Great Northern and Thameslink passengers are experiencing this morning.

"This is due to various issues, including overrunning engineering work, signal and track faults, as well as an issue on a freight train.

"We would like to reassure passengers that we are working to resolve these issues as quickly as possible and we thank them for their patience during this time.

"We would urge passengers to check before travelling via National Rail Enquiries or their train operator."

In Knebworth there have been multiple signalling problems causing severe delays on the northbound lines, affecting trains travelling away from London on their journeys between Welwyn Garden City and Stevenage.

This has also led to delays for southbound trains on their return journeys.

The signalling problems have been resolved but there is still congestion in the area.

There was also a points failure earlier at Alexandra Palace, but this has now been resolved.

This was preventing trains from using some routes over a junction in the area.

In Cuffley - on the route via Hertford North - signalling problems were causing delays, but these have been resolved and trains will no longer be held at signals in the area.

Trains between Stevenage and London may be cancelled or delayed by up to an hour.

Disruption is now expected to continue until at least 12 noon.