The cost is officially estimated to be £42.6bn and could rise to more than £51bn if, as expected, the scheme incurs VAT. Opponents foresee further increases and have predicted an eventual bill of £80bn for taxpayers.

Who stands to gain from the project and who will be the losers?

The government has published detailed maps of the route to be taken by the first stage, leading to calamitous falls in the value of many nearby properties.

Towns and cities which are near the route but not linked to HS2 fear that their economies will suffer as businesses are attracted to Birmingham and the northern ends of the line. Current fast train services are due to suffer drastic cuts in the wake of HS2 and some major development plans are now deemed to be at risk.

Meanwhile, economic advisers in the three major cities are planning for billions of pounds worth of benefits as travel-times and congestion on the existing network are reduced.

Gerry Northam reports from areas which expect to benefit from HS2 and those which could lose out and asks what lessons can be learned from the impact of Britain's first high-speed rail project - HS1 in Kent.

Producer: Ian Muir-Cochrane

Editor: David Ross.