Rail operator Northern has revealed that its plans to run longer six-carriage trains in and out of Yorkshire's biggest railway station will not become reality until the end of 2021.
The firm blamed delays by government agency Network Rail in building longer platforms at Leeds station as it admitted the plans to provide 50 per cent more capacity at peak times were now happening two years later than expected.
But rail officials have suggested that the operator knew in 2017 that the £161m upgrade of the station which would make room for the longer trains would not be completed this year as originally planned.
And with the publication of a major review into the railway industry expected later this year, the announcement has prompted calls by a leading lobby group to hand more powers to oversee infrastructure improvements to northern leaders.
Northern has been heavily criticised in the last year after the disastrous introduction of a new timetable in May led to widespread disruption and delays across the North.
It is understood that in 2017, two years after the franchises to run rail services were handed to Northern and TransPennine Express, Network Rail decided that the redevelopment of Leeds and the longer platforms could not be finished until the end of 2021.
In 2018 a letter from the Rail North Partnership, which manages Northern, confirmed that the station would not be ready for the longer trains in 2019, though the Department for Transport insists this was a "contractual requirement" confirming what was already known.
In November last year Network Rail posted details of the work at Leeds station online, including a new platform known as platform zero, longer platforms and a major upgrade to signalling. It said the work would be completed in 2021.
In a statement to The Yorkshire Post, the firm said it was introducing £500m of new trains across its network in the next 12 months with free WiFi, at-seat power sockets, air conditioning and extra space.
A spokesman said: “The new trains have been planned and ordered as two or three carriage diesel trains, and three or four carriage electric trains.
"The plan for Leeds North West services is to join two of the new three-carriage electric trains together to create a six-carriage formation, providing 50 per cent more capacity at peak times than today.
“However, Network Rail delays to building more platform capacity at Leeds station means that the six carriage formation trains will run when that platform capacity is created, which is expected by December 2021 rather than the original date of December 2019.
“In the meantime, from December 2019, Northern will introduce four carriage, brand new electric trains for customers on the Leeds North West routes, providing a higher standard of customer experience than today.”
A Network Rail spokeswoman said the platform scheme had previously been paused and it "had not committed to a date for it to be delivered".
She said: "We continue to work with industry partners on this project and we look forward to passengers reaping the benefits when it completes in 2021.
“Meanwhile our work to improve the overall experience for passengers at Leeds continues as a major project to install a new, transparent roof over the old, gloomy concourse is well under way.”
The Department for Transport said it was committed to working with Northern to "achieve the complete removal of the outdated and unpopular Pacers".
A spokeswoman added: "Northern is also investing £500 million on the roll out of 290 brand new carriages for its network, with all other trains refurbished.
“By the end of this year, more than 2,000 extra services will be provided each week and there will be space for 31,000 extra passengers on Northern trains.”
A review of the railways, being carried out by the former British Airways boss, Keith Williams, is due to conclude later this year.
And Henri Murison, director of the Northern Powerhouse Partnership, said the case to "devolve control of the railway to us here in the North has never been stronger”.
He said: “At the moment the Rail North Partnership, based in Leeds and in part answerable to our civic leaders, has no oversight over infrastructure improvements to avoid such errors.
"To avoid any further such mistakes and failures of co-ordination, Northern Powerhouse Partnership have called for schemes like the upcoming Trans Pennine Route Upgrade to have the funding devolved.
"Working with a stronger and reformed Network Rail, led by the new Chief Executive Andrew Haines, we can stop one official at one desk in Whitehall giving instructions which are impossible to follow due to the decisions and actions of someone who may be on the same floor, but neither understands nor can ever be properly supervised."
Susan Hinchcliffe, who chairs the West Yorkshire Combined Authority, said the current rail franchising system was "letting down not just the passenger but the northern economy".
She said: "Passengers are frustrated, they are frustrated because they don't understand why when they try to to get on a train it is full and they can't get on it.
"They can't understand why when they try and get on a train it is cancelled. They need to see greater accountability."