One of the UK’s worst-performing railway operators issued a “do not travel” alert on Wednesday, blaming an internal computer failure that resulted in a third of all its trains being cancelled yet again. Andy Burnham, the mayor of Greater Manchester, urged the government to “step in – now” after TransPennine Express (TPE) urged people not to travel on Wednesday. He said the firm should be given a formal notice to improve or be stripped of its contract, as happened in autumn with Avanti West Coast, which has the same parent company, FirstGroup. The issues were “entirely of the company’s own making”, said Burnham’s counterpart in West Yorkshire, Tracy Brabin. TPE operates trains on three key routes from Liverpool and Manchester to Leeds, Sheffield, Hull, York, Newcastle, Edinburgh and Glasgow. Kathryn O’Brien, TPE’s customer service and operations director, blamed “a significant rostering system issue”, which was resulting in “a high level of unplanned cancellations and disruption across our network”. A TPE spokesperson clarified this was “a computer/software issue rather than a staffing problem” and that the firm anticipated cancelling “around a third of our timetabled services today”. But for months the company has been cancelling dozens of trains at 10pm the night before travel, using something called the “P-code”, which means they don’t “count” in official statistics and in effect disappear from the timetable. On Monday 12 December, the first full day of the new winter timetable, the firm cancelled 32% of trains. This was before any talk of IT problems. Burnham said the government should issue TPE with a formal warning before Christmas. “TPE needs to be explicitly told that if it doesn’t improve by mid-January, their contract will be removed. The government has got to stop this chaos and make clear that TPE has one last chance. At the moment, they are not even on probation,” he said. Brabin said: “It is completely unacceptable that TransPennine Express have told passengers not to travel because they have cancelled so many of their services today. “This is a problem entirely of the company’s own making. I and other northern mayors have been calling on the government to put them on notice to improve or have their franchise taken away. The government needs to do this now and get an urgent grip.” O’Brien apologised to customers and said the firm was “working hard internally and with our system provider to resolve the situation as soon as possible”. She added: “We are doing all we can to keep customers on the move but, while problems persist, we advise customers not to travel and to seek alternative means of transport.” Official statistics from the Office of Rail and Road suggested TPE cancelled 6.4% of trains in the quarter to 30 September. But the firm’s real cancellation rate has been far higher when P-coded cancellations are included, running at between 20% and 32% in recent weeks. Various Transpennine employees told the Guardian that most drivers and conductors knew their schedules at least two days in advance, so questioned why an IT failure was able to wipe out a third of the timetable. But a spokesperson for TransPennine Express said: “In line with agreed processes, our train conductors are allocated a roster in advance, ensuring they know what shift they will be working. To try to minimise cancellations and mitigate the effects of the issues we have faced in recent months, we are currently allocating conductors to specific services on a day-to-day basis. “The technical issue we have experienced today – which has affected all routes – meant that, at the start of the day, train crew were not effectively matched to existing services.” The spokesperson went on: “We have enough train crew to operate our services under normal conditions and more drivers than ever before. The significant issues we have faced today are not linked to crew availability. “However, we continue to deal with high levels of sickness and an unprecedented training burden and made clear that the delivery of the new timetable would be challenging from the outset whilst such problems persisted.” A representative of the RMT union said the day’s chaos showed “Transpennine are not fit to run a bath, let alone a train franchise”. A Department for Transport spokesperson said: “The level of disruption on the rail network is well above what should be expected and passengers, particularly in the north, have suffered for too long. “Following his meeting with northern mayors, the transport secretary has agreed a four-pronged approach to improve rail services in the region. We will continue to monitor service levels closely and pressure operators to deliver improvements.”