Passengers on the east Midlands rail network are still experiencing delays despite an upgrade to the track.

A £70 million investment was meant to reduce journey times to London by eight minutes but the project has been beset with problems. This means that commuters have been experiencing disruptions of between two and three minutes.

Network Rail admitted it had been aware of the setbacks in late November, when it became clear that the project would not be completed on time. As a result, delays have been caused by the remaining works still taking place on the line. The company claimed however that some passengers were still benefitting from a faster service.

A spokesman added: "We apologise that we have so far been unable to deliver all of the promised journey time improvements on all our train services."

When the track is fully operational, trains will be able to reach a top speed of 125mph, cutting the journey time from Nottingham to London down to 91 minutes.