The rail industry has "collectively failed" Northern passengers who suffered delays, cancellations and chaos when new timetables were introduced last week, the Transport Secretary has said.
Chris Grayling said in a letter to the region's MPs that the level of disruption on Northern rail last week was "wholly unsatisfactory" and the scale of the chaos "far outstripped any expectation".
He wrote: "I am frustrated that what should have been good news for passengers, with the introduction of new services, new routes and expanded capacity has had such a poor start.
"The industry collectively has failed the passengers it serves. A combination of delayed Network Rail infrastructure works and reduced planning time meant that the new timetable was finalised much too late to permit adequate logistical planning for the timetable changes."
He added: "We were aware that there might be some disruption in the early days of any new timetable change of this size, but the scale of the problem has far outstripped any expectation.
I am determined both that the problems are dealt with as quickly as possible, and that this is not repeated in the future."
Mr Grayling blamed Network Rail, the publicly owned infrastructure operator, for failing to deliver electrification between Bolton and Preston in time for the new timetable.
This "had already caused severe operational planning issues" as the introduction of electric trains had to wait, leaving a shortage to cover the increased number of services planned.
"The reduced time to plan a modified timetable has made this situation much worse," he said.
"A significant number of Northern’s services have had to be changed at very short notice leaving no time to resolve train scheduling issues which have arisen."
The Transport Secretary also took Network Rail's "wholly unacceptable" approach to timetabling, stressing it has caused "chaos" for train companies by leaving it too late to ensure the new arrangements would not create conflicts across the railway.
Incoming chief executive Andrew Haines and the current Network Rail leadership have now been asked to ensure timetabling arrangements are improved in future.
"Until this has been done, I will insist on a gradual approach wherever possible to timetable change and not the significant changes we have seen this month," Mr Grayling said.
The Tory Minister also claimed strikes have "exacerbated the situation".
He has been in regular contact with Transport for the North (TfN), which manages the franchise alongside his own Department for Transport, as well as Network Rail and Northern.
"We have insisted that TfN and the two rail organisations put whatever resource they need to into resolving the situation, and in making sure that there is proper leadership of the recovery effort," he said.
The Transport Secretary offered to hold a meeting for MPs whose constituents have been affected next week, and has asked Network Rail and Northern Rail to organise a briefing.
His "Dear Colleague" letter concluded: "Once these problems are resolved, we will have a much better service for passengers. That is small comfort to them when things are not working as they should, but once we are through this difficult period we will have a better railway – particularly once all the new trains start to arrive later this year."