Frustrated train commuters in the North should get "substantial" compensation and fare reductions after a new timetable brought chaos to the network, the Mayor of Greater Manchester said.
Andy Burnham said train operator Northern was in the "last chance saloon" after axing hundreds of services, delays and cancellations following the new timetable introduced on May 20.
Northern has apologised and last Friday evening introduced an "interim" timetable, starting on Monday, removing 165 trains - 6% of services.
Areas affected include Manchester, Liverpool, Blackpool and the Lakes Line between Oxenholme and Windermere.
In a letter to the Chair of Transport for the North (TfN) John Cridland, the mayor says that Northern is likely to benefit financially from the operation of the reduced timetable and if the company is not prepared to fund the compensation package and reduce fares voluntarily, then fines should be imposed to pay for it.
Mr Burnham also called for Northern passengers on affected routes to be allowed to use their tickets on other modes of transport such as TransPennine Express trains, buses and Metrolink.
He said: "Northern have already left people seriously out of pocket and turned their lives upside down with their chaotic services.
"I have heard countless stories of people forking out for taxis, hire cars, hotels and extra childcare but unable to get compensation for it.
"Now that Northern are unilaterally cancelling thousands of services - that many season ticket holders have already paid for - passengers must be properly and fully compensated.
"There must also be a general reduction in fares for all passengers on routes affected by these changes.
"Northern are set to benefit financially from this emergency timetable. It is the company, and not the passengers, who should pay the price for their mismanagement.
"As far as I am concerned, this emergency timetable represents the last chance saloon for Northern.
"They are causing too much damage to the economy of the North to be allowed to inflict their miserable, unreliable services on us any longer.
"If they are not providing the promised new May timetable by early August, then steps should be taken to strip the franchise from them."
Northern insists it will still run more trains than it did before last month's timetable change, and expects to "get back to a full timetable service by the end of July".
The firm's managing director David Brown has apologised for the "unacceptable service" and said they are working hard to fix the problems.
Elsewhere London Mayor Sadiq Khan said disruption to Govia Thameslink Railway (GTR) services is damaging the "international reputation" of the capital and said the firm should be stripped of its franchise to run services.
On Friday GTR - which consists of Southern, Thameslink, Great Northern and Gatwick Express - saw almost one in 10 (9%) of its trains either cancelled or more than 30 minutes late.
Northern's record was even worse at 16%.
Britain's rail timetable is updated twice a year, but the latest version has many more changes than normal in a bid to improve punctuality and account for extra services and capacity following billions of pounds of investment.
Transport Secretary Chris Grayling has said he is in "regular discussions" with train operators but the new timetable will ultimately deliver hundreds more services.