Engineering work which overran causing travel chaos for thousands of train passengers over Christmas had been a project "completely out of control", a rail company boss has told MPs.

Network Rail, which was responsible for the four-day overrun on the West Coast Main Line still "didn’t seem to know" what had gone wrong, Virgin Trains managing director Chris Gibb told the House of Commons transport committee.

Both he and Virgin’s chief executive Tony Collins told MPs they had concerns that the work might overrun and had told NR of their fears.

Mr Gibb said that the project at Rugby, Warwickshire, had been planned for a year. He went on: "But with 18 days to go they were still frantically moving things around. It had all the signs of a project completely out of control.

"Communications between the project management teams and NR were not good."

Asked what went wrong, Mr Gibb replied: "They (NR) don’t seem to know – that’s the short answer. I knew it was a huge project but other projects have been big and they have been completed on time.

"I sought assurances during December that it would finish on time and I was told it would."

The West Coast work should have been completed in time for normal services to return on the key London to Scotland route on December 31.

But early in December NR said it needed an extra day to do the work and in the event the work dragged on so that services were not returned to normal until January 4.

NR has started its own inquiry into the overrun and the Office of Rail Regulation has also mounted an investigation and could fine NR.

Mr Collins told the committee: "The ORR should not have been reactive to the problem. They should have been more proactive. They had enough powers to investigate the issues arising.

"One thing we will want to know is why didn’t they (ORR) put checks and balances in place to ensure the work was done properly." The ORR fined NR for an overrun of signalling work at Portsmouth in 2006. Mr Collins said yesterday that the ORR should have put checks in following the Portsmouth problem and that they should have used the train companies to identify the problems.