A replacement coach service will connect passengers with other trains

Virgin has accused Network Rail of breaking its licence agreement by closing part of the West Coast mainline near Rugby at short notice.

An estimated 60,000 passengers expected to use the line on New Year's Eve face an extra hour on their journey times.

Network Rail has apologised but insists key work must be done over the festive period when passenger numbers are down.

The line was due to be closed on 27 December for three days but Network Rail added an extra day of work, which is part of the �8bn upgrade of the line.

The Office of Rail Regulation said it is investigating the complaint but ruled the work must go ahead.

Shadow transport secretary Theresa Villiers said: "Scheduling track works on December 31 is misguided and Network Rail should think again about this decision and the inconvenience it will cause for passengers."

Network Rail is extremely sorry and apologises to passengers for the inconvenience Network Rail spokesman

The latest disruption will affect mainly Virgin Trains to and from the West Midlands, north Wales, north-west England and Scotland.

A coach service will replace trains between Northampton and Birmingham International.

Some London Midland and First ScotRail Sleeper services that would have passed through Rugby will also be affected.

Anthony Smith, chief executive of Passenger Focus said: "This is unbelievable. Thousands of passengers have booked or planned New Year travel in good faith.

Newspaper adverts

"We feel very let down and want re-assurances that the huge amount of engineering work planned for next year will not run into similar problems."

Up to 60,000 travellers are expected to use the line on New Year's Eve and Virgin has warned them in a series of newspaper adverts to add at least an hour to journey times.

A message on its website guarantees that every passenger will get to their destinations in time to celebrate the New Year.

Chris Gibb, managing director of Virgin Trains, said: "I am extremely disappointed that Network Rail have informed us of this new disruption at such short notice. Network Rail have insisted this work goes ahead on this crucial travel day."

'Key work'

The engineering work is part of a major overhaul of the West Coast Main Line which began in the mid-90s.

A Network Rail spokesman said: "Work will be ongoing for most of the next year, but the Christmas period is the last major opportunity we have to do key work while passenger numbers are down during the relatively long holiday period."

He added: "It was only realised at the beginning of December that work was falling behind. Rail companies are usually given 12 weeks notice of engineering work. Virgin were told only at the beginning of the month, so that is very late.

"Network Rail is extremely sorry and apologises to passengers for the inconvenience."