The High Speed 2 (HS2) railway project schedule is “too ambitious”, according to a National Audit Office (NAO) report released today.
The NAO said the impact of cost and schedule pressures risked the economic benefits the scheme is intended to bring for areas across the country.
NAO head, Amyas Morse, said: “HS2 is a large, complex and ambitious programme which is facing cost and time pressures.
“The unrealistic timetable set for HS2 Ltd by the Department [for Transport] (DfT) means they are not as ready to deliver as they hoped to be at this point.
“The department now needs to get the project working to a timescale that is achievable.”
The report commented that the DfT has asked HS2 Ltd to assess the impact of extending the timetable for phase one of the project by up to 12 months.
Phase one of HS2 involves constructing and maintaining a high-speed rail link between London and the West Midlands.
This is currently forecast to cost £27.4bn, exceeding available funding by £204m.
In addition HS2 Ltd only have a 60% confidence level that the 2026 target date for phase one completion will be achieved, which the DFT has asked to be raised to 80% without increasing costs.
Phase two of the project forms a Y-shape, linking Birmingham with Manchester and the North West.
The estimated cost of this phase is at an earlier stage to that of phase one, but was deemed to be £7bn over the funding available at the government’s 2015 Spending Review.
However, previous work by the DfT, HS2 and the Cabinet Office have identified potential savings of £9bn, £2bn of which has been secured.
The overall budget for the project is £55.7bn.
Despite these challenges HS2 Ltd welcomed the report, claiming that the project was on track to deliver its strategy on budget.
“Major engineering projects such as HS2 are a learning curve in which the method of construction as well as cost control evolve,” HS2 said in a statement.
“At each stage the combination of value engineering, plus the lessons we have taken from international best practice and innovation is helping HS2 both to drive down cost and increase our confidence in our ability to deliver, and that is a process that will continue.”