Network Rail is responsible for maintaining the railways
Train passengers face disruption from weekend engineering work for years to come, the rail regulator has said.
By 2014 the situation would have eased but there would still be "some way to go" to a full seven-day railway, said the Office of Rail Regulation.
The regulator also said funding for Network Rail, which runs the railway infrastructure, should be £26.5bn for 2009-14 - despite it wanting £29.5bn.
Network Rail said its plans to meet rising demand could be put at risk.
The budget was revealed in the regulator's "draft determinations" containing Network Rail's funding and projects for five years from April 2009. A final decision will be made in October.
The regulator's performance director Michael Lee said: "Network Rail is very conscious that there is too much disruption to services. It is going to take a long time to achieve everything that can be done."
Commenting on the situation at the end of the five-year period, he added: "There will be much less disruption by then but there will still be some way to go."
The regulator backed plans for major projects contained in the government's railway White Paper.
- The Thameslink scheme
- Rebuilding Reading station
- Redeveloping Birmingham New Street station
- Work on the East Coast line from Peterborough to Doncaster
- A new Glasgow airport rail link
- A new line from Airdrie to Bathgate in Scotland
The regulator also supported government targets for trains running on time by 2014 of 92.6% in England and Wales, and at least 92% in Scotland.
Its chief executive Bill Emery said it was a "good package for passengers, for freight customers and for taxpayers".
However, Network Rail chief executive Iain Coucher described the funding settlement as "insufficient".
Anthony Smith, chief executive of customer watchdog Passenger Focus, said it was correct that pressure was applied to Network Rail.
But he added: "Forcing them to scrimp and cut corners will mean a poorer service for passengers."
Shadow transport secretary Theresa Villiers said the announcement was a "step in the right direction" but that "much more" should be done to improve Network Rail's performance.
Liberal Democrat transport spokesman Norman Baker accused the government of failing of to plan ahead to meet a projected increase in passengers numbers beyond 2014.