Road building now costs 40% more than originally estimated because the HA has failed to get a grip on spiralling costs and long delays, the MPs said.

The committee attacked the HA's "poor track record" on delivering schemes on time and the Department for Transport for not being rigorous enough in its oversight.

Austin Mitchell, veteran Labour MP for Grimsby, also described Sir David Rowlands, permanent secretary of the Department for Transport (DfT), as like a "petulant, naughty schoolboy" during the cross-examination in preparation for the report.

Committee chairman, Edward Leigh, criticised both the HA and the DfT after it emerged that the total cost of the 36 schemes completed in the year to last September was 40% more than expected.

He said: "What would you think of a builder whose work on your house ended up costing 40 per cent more than his original estimate? That's the position the HA is in over its multi-billion road building programme."

A spokesman from DfT told B&E online that the major cause of inaccurate estimations was inflation and that the report’s concerns had already been addressed.

He said: “We commissioned our own report, The Nichols report in March because we were concerned about it. Since then we have made a number of recommendations, which are now in place.

“The Highways Agency are already implementing improvements using cost ranges rather than point estimates to reflect uncertainty in schemes early development, they’ve improved risk assessment processes to account for early uncertainty and they’ve strengthened project management processes throughout the project life cycle.

“We’ve already put a lot of these improvements in place. The problem they’re talking about hopefully should be a thing of the past.”