HS2 rail benefits to economy 'unclear', says National Audit Office

The benefits of the HS2 high speed rail project on the economy are unclear, the National Audit Office (NAO) has warned.

The NAO said in a report that it had "reservations" about how the London-to-Birmingham link would deliver growth, adding that the project had an estimated £3.3bn funding gap.

But Transport Secretary Patrick McLoughlin said the NAO's conclusions were based on old data.

Richard Westcott reports.