Stagecoach, the bus and rail operator, has cast doubt over Network Rail's ability to complete crucial engineering work in time for a planned December timetable change.

Virgin Trains, which is 49 per cent owned by Stagecoach, is planning to run 30 per cent more trains from London to Manchester from the end of the year if the work to upgrade the West Coast Main Line is completed.

However, Stagecoach yesterday questioned whether Network Rail would be able to complete the work that quickly.

Brian Souter, chief executive of Stagecoach, said that a decision would be taken in August on whether the timetable could be achieved. He said it may be more realistic if timetable changes were moved to next Easter.

“We have always been concerned that the programme is very ambitious. That is not to say that Network Rail won't deliver as the company has more track access this summer,” he said.

Ian Dobbs, chief executive of Stagecoach's rail division, said he was working closely with Network Rail and the two companies would approach the Government and the rail regulator jointly by September if it looked as if the timetable could not be fulfilled.

Hundreds of thousands of passengers on Virgin Trains, which Stagecoach owns jointly with Sir Richard Branson, were caught up in disruption over the new year and at Easter, after scheduled engineering work on the West Coast Main Line overran.

Network Rail received fines of £14 million and promised that it had stepped up its project management of the engineering work.

A spokesman for Network Rail said: “We have put together a robust plan that will involve a few more closures of the railway. The Rail Regulator is happy with this plan.”

Despite the uncertainty surrounding work on the railways, Virgin Rail has seen an 11.2 per cent increase in like-for-like passenger growth. Operating profits for Stagecoach's share of Virgin Rail have increased by 238 per cent, from £12.4 million to £41.9 million.

The strong performance was reflected across Stagecoach, which announced an 8 per cent rise in full-year pre-tax profit from £162 million to £174.4 million.

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