MPs from the Commons public accounts committee have called for the Department of Transport to provide more detailed evidence to support the estimated £50 billion investment. Presenting the committee's findings, chairperson Marget Hodge said:
The pattern so far has been for costs to spiral - from more than £16 billion to £21 billion plus for phase one - and the estimated benefits to dwindle.
In my committee's experience, not allowing enough time for preparation undermines projects from the start.
More top news
Very warm in the southeast tomorrow
An astronaut on the International Space Station has shared his experiences from outer space in the first Twitter chat from the craft.
Kate is now an advanced diver after passing a Professional Association of Diving Instructors (PADI) advanced open water diver qualification.