Transport for the North issued the warning following the publication of the Government’s long-awaited £96.4bn Integrated Rail Plan, which scaled back the Northern Powerhouse Rail (NPR) and High Speed 2 (HS2) projects.
The eastern leg of HS2 will now only run to East Midlands Parkway, and trains will then continue on an upgraded line to Sheffield but not reach Leeds.
The revised NPR project will see the Government spend £17bn on building a high-speed line between Warrington and Marsden and £5.4bn on upgrading the Transpennine Main Line,
The IRP also promises a “comprehensive package of upgrades” on the East Coast Mainline, between London and the North East, to reduce journey times and increase capacity.
The Government said these plans provide better value for money and passengers will see the benefits up to 10 years earlier, as some NPR services will begin running before 2030.
But in a report, Transport for the North said: “By choosing to focus investment on upgrading existing routes, the North is likely to see sustained closures and disruption through the next 10 to 15 years at a critical time for encouraging behaviour change and use of rail for longer distance trips.”
South Yorkshire Mayor Dan Jarvis said: “What we’re facing in the North is years of chaos and delay on our railway network because of a complete failure to invest in new lines and because of the Government’s attempt to do everything on the cheap, in a way that simply would not be acceptable in the South of England.
“It seems to me that across the North we continue to accept what is barely a second class service, it’s more like a third class service.
“I just think it frankly makes a complete mockery of the Government’s commitment to level up the North of England.”
The Labour mayor, who is also the MP for Barnsley Central, is calling on the Government to stick to the original plans for HS2 and NPR and said MPs should be allowed to vote on the IRP.
Robbie Moore is one of a number of Conservative MPs in the North who were disappointed by the Government’s revised plans for NPR.
The MP for Keighley and Ilkley is urging the Government to build a line between Liverpool and Leeds, and ensure Bradford is included in the route.
“ A £96bn package is a great announcement by the Government and it does benefit a lot of areas, particularly in the Midlands. It will also benefit those that live directly on that Transpennine route where the upgrades are taking place.
“But the Bradford district has been completely shortchanged,”
He added: “For Keighley, Manchester is only 46 miles away but it takes just over two hours to get there by train. It is vital that Keighley and Bradford get direct links west, to Manchester, to unlock those economic opportunities.”
Transport for the North had been drawing up the business case for NPR, but the Government took charge of the project after publishing the IRP in November.
The Department for Transport has disputed Transport for the North's claims about prolonged disruption.
A spokeswoman said: "We don't recognise this characterisation, with many of the changes we're introducing likely to result in less disruption than under TfN's plans.
"We are focussed on bringing benefits to the North sooner, and will of course be seeking to minimise disruption to communities wherever possible.
“Our Integrated Rail Plan outlines a historic £96bn investment in our railways, bringing benefits faster and at better value to the taxpayer.”