The UK rail industry plans to run 6,400 more passengers trains every week by 2021.
Analysis from the Rail Delivery Group (RDG), which represents train operators and Network Rail, found projected timetable improvements for the next four years show 1,283 more trains a day (6,417 a week) will run Monday-Friday – an increase of 11 per cent.
The improvements are part of the £50 billion Rail Upgrade Plan announced by the government to tackle the “capacity crunch” on the network and improve reliability.
However, rail unions rejected the figures as hollow promises and PR spin.
"Like most people we will believe this when we see it,” said RMT general secretary Mick Cash. “There simply aren't the trains and staff available to make this plan happen. Fault for that lies smack at the door of over two decades of privatisation.
"The train operators are already struggling to run current services and timetables due to a chronic lack of investment and the drive across the industry is to hack back on staff in the search for fatter profits. Our guards are in the front line of that attack on jobs and safety.
"With the British public paying the highest fares in Europe to travel on rammed-out and unreliable trains the only solution to this on-going transport crisis is public ownership."
RDG chief executive Paul Plummer said there had been a "capacity crunch" for years as passenger demand increased.
"That's why we're delivering billions of pounds of improvements and reversing decades of under-investment...
"It will break bottlenecks, untangle tracks and harness technology so that more trains can run to more places more often."
Satisfaction and punctuality on UK rail services is at its lowest in years and regulator, Office of Road and Rail, recently published a damning report criticising Network Rail.
Manuel Cortes, general secretary of the Transport Salaried Staffs Association, said: "While I welcome the RDG's aspiration... I'm weary of their spin.
"I'm sure many passengers... will be asking themselves why rather than always promising jam tomorrow, they simply just don't get on with running quality train services today.
"UK passengers pay the highest fares in Europe for substandard services and I expect they too will respond to this latest 'jam tomorrow' announcement with derision."