Liberal Democrat MP Norman Baker has moved from his role as crime prevention minister to a new Home Office job.
Network Rail are not "managing their day to day activity as well as we would like" and causing avoidable delays and cancellations, a transport minister has said.
Norman Baker told Daybreak he had already spoken to the chief executive of Network Rail about their poor performance.
"I made it plain to them that with the £37 billion we're investing in the traditional railway in the next five years, we want it to be delivered efficiently and effectively."
Britain's railways are not up to scratch because Network Rail has failed to upgrade them, despite having billions of pounds of public money invested, a regulator has said.
Failures in the firm's drainage and embankment systems have increased tenfold during the past two years, the Office of Rail Regulation (ORR) revealed.
It found the company paid "inadequate attention" to this area which slowed down preparation for adverse winter conditions.
There was also a backlog of maintenance work and found improvements in efficiency have slowed down, following an annual assessment.
Rail Minister Norman Baker is expected to confront bosses again this week over continued delays and an apparent lack of preparation for bad weather.
He accused Network Rail of failing to rectify numerous problems "of its own making".
– Norman Baker, Liberal Democrat Transport Minister
I think that it is a misunderstanding that the amount of work an MP does is reflected by the number of days that Parliament sits. It isn't.
Some MPs work bloody hard all year round and others don't.
I just spoke to the Liberal Democrat Transport minister Norman Baker who said he had "no idea" about the Lord Rennard allegations until the Channel 4 report last week.
Transport Minister Norman Baker has told ITV News that he would like to see the end of above inflation rail fare increases but, "we have to invest in the future."