Only two weeks after Network Rail announced that 1800 maintenance jobs are to be cut in a bid to improve efficiency, the Rail Regulator has said NR's spending plans are "still inadequate".

The Office of Rail Regulation Chief Executive, Bill Emery, said Network Rail ‘must now rise to the challenge’ of its five-year spending plan - known as Control Period 4 (or CP4).

He explained: "We are six months into CP4 and we believe certain areas are still inadequate.

"It is crucial that Network Rail make the changes so that train companies and funders are clear on how it intends to deliver the £8bn programme of enhancements."

The Rail Regulator also said that Network Rail still may not be doing enough to improve performance on the West Coast Main Line - Europe's busiest mixed traffic rail route.

Passenger train punctuality over the whole Network Rail system - measured as trains within either 5 or 10 minutes of right time at their destinations - reached 90.9 per cent at the end of the April-June quarter, 0.5 per cent up on a year before.

But poor performance on the West Coast main line - "largely due to high levels of asset failures" - has continued to affect Virgin Trains and London Midland, said ORR in its latest Network Rail Monitor.

At the end of the April-June quarter Virgin's punctuality was "just 81 per cent," said the ORR.

"We made clear to Network Rail in May that this is unacceptable and that we would be likely to take enforcement action unless it tackled the issue immediately and effectively."

Bill Emery added: "There is no room for complacency and Network Rail must stay focused. The West Coast main line is a route which has seen massive investment. Poor performance is simply unacceptable, to Virgin Trains and its passengers and to the other train operators using the line.

"We continue to monitor the situation closely, and we are ready to take more formal action if necessary.

"ORR has yet to agree Network Rail's plan to improve performance for the remainder of the year. We will be shortly reviewing that with Virgin Trains," he added.