Thousands of rail travellers will face a further day of disruption on the West Coast main line tomorrow after Network Rail confirmed that engineering works would continue on one of the country's busiest railway lines on Thursday.

A spokesman for the rail group said that a further inspection of the engineering site would take place tomorrow morning to establish if the line could open over the weekend.

In the meantime, an estimated 60,000 passengers will be forced to take buses between Northampton and Rugby due to an overrun on planned engineering works, adding about two hours to their journey.

The West Coast disruption came as London's Liverpool Street station remained closed due to over-running engineering works, creating misery for hundreds of thousands of commuters in the capital. The London terminus has been shut since December 23 and Network Rail faces penalties for both overruns.

Transport for London confirmed this morning that Liverpool Street station had not reopened due to “problems”. A notice on its website said that due to a late finish to engineering works.

One services were not serving Liverpool Street station. Passengers were advised to use alternative London Underground routes into London or buses. The station was closed while a bridge outside was demolished as part of the East London Line extension project.

The One train company advised passengers not to travel into London if their journey was “not important”.

A National Rail spokeswoman blamed a shortage of specialised engineering staff for the delay in Liverpool Street being reopened. “We have pulled in everybody we possibly can in order to get the West Coast work completed,” she said.” We deeply apologise for the inconvenience caused.”

She added that it was hoped that the station would be open in time for today’s evening rush-hour.

The spokeswoman continued: “We are holding an inquiry into what has gone wrong.”

The travel woes for passengers came on the same day as new higher-than-inflation fare rises took effect. The level of the rises have been bitterly criticised by opposition politicians and rail passenger groups.

The problems in East London will add to Network Rail's New Year hangover. The rail infrastructure group has already missed a series of deadlines on a crucial section of the West Coast main line, to the fury of passenger groups and Virgin Trains, the rail operator.

Chris Gibb, managing director of Virgin Trains, said: "This is a major inconvenience to tens of thousands of our customers returning to work tomorrow and it is not acceptable. It is the third successive day that this project has overrun, and this makes us deeply concerned about the delivery of the project."

Network Rail teams were still working this morning on a £400 million signalling scheme at Rugby. Passengers are being advised to use alternative routes, run by competitors of Virgin.

However, the cheapest advanced purchase tickets, which will have been bought by many people returning home after spending time visiting family and friends over New Year, will not be accepted by other train operators, except East Midlands Trains and Chiltern Railways.

Last year, Network Rail fined £2.4 million for failing to complete a signalling scheme at Portsmouth on time.

Virgin Trains has already referred the engineering overrun to the Office of Rail Regulation because it argues that it was given insufficient notice of the engineering works. However it failed in its attempt to get the ORR to issue a provisional order preventing the line closure at Rugby on December 31.

The Office of Rail Regulation (ORR) said today that it had launched an urgent investigation into the engineering overruns.

The ORR added that it would review the planning and management of the works, to assess NR’s project planning, its management and resourcing of the projects, and its dialogue with train operators once it became clear that the works would not be completed on time.

ORR chairman Chris Bolt said: “We fined Network Rail for its project planning and management failings after it failed to complete the Portsmouth resignalling project last Christmas. It is extremely disappointing to have a repeat of that experience, on key parts of the network.”

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