The derailed train was on its way to Glasgow More detail

Network Rail had hoped to open four of the six platforms following the derailment on Tuesday morning, by 0600 BST.

But three trains stranded on platforms since the derailment, delayed work further.

The platforms eventually opened at 0830 BST.

On Wednesday, the derailed GNER locomotive and carriages were removed from the tracks after two days of delays for commuters.

GNER was only able to run two-thirds of its services on Tuesday and Wednesday after the incident.

A spokesman for Network Rail added: "We have had to repair the complex signal and points system at the throat of Kings Cross and tonight we are testing the systems to ensure they are working safely."

But platform four, where the train derailed, will remain closed for two weeks while points are replaced - although it should not affect train running times.

'Neglect' factor

Maintenance contractors Jarvis Rail, who are being investigated over the Potter's Bar train crash, had previously been carrying out overnight engineering work on the stretch of track where the train derailed.

The company confirmed the points should have been left so trains would continue straight ahead, but staff had "neglected" to reset them.

An investigation has been started by the Heath and Safety Executive.

Passengers are advised to ring National Rail Enquiries on 08457 48 49 50 or check on the National Rail website www.nationalrail.co.uk before setting out.