The HS2 high-speed rail project has an estimated £3.3 billion funding gap which the Government has yet to decide how to fill, a report from a Whitehall spending watchdog said today.
It was not clear how HS2 - which runs through Tory heartlands and is bitterly opposed by some - would deliver and rebalance economic growth, the report by the National Audit Office (NAO) added.
The timetable for planning phase one of the project - from London to Birmingham with work due to start in 2016/17 - was "challenging", the NAO said.
This challenging timetable "makes delivering this work difficult and increases the risk that the programme will have a weak foundation for securing and demonstrating success in the future", the report said.
More top news
Thousands of people have signed a petition calling for 'Britain's Hardest Grafter' to be scrapped before filming even begins on the series.
Apple has found a solution to the text message bug that was able to crash users' iPhones.
A giraffe has been born in front of visitors to a zoo in Devon.