There are few Labour ideas that garner any Conservative support these days, but the ‘alternative’ HS2 route, via Heathrow, has certainly sparked interest.

Some suggest the alternative route could provide a compromise between those who desperately oppose cutting through the Chilterns and those who are pressing for a faster connection between London and Birmingham.

But there is still much research that needs to be carried out and several questions to be answered before this could be a viable alternative route.

The Bow Group’s cost estimate of the comparative route suggests it could save £1.7bn. If this is entirely due to leaving the cost of the station at Heathrow to be covered by private investors, then it could be argued that the original line could save money in a similar way.

Additionally, the London-Birmingham journey time is estimated to be a minute faster than the Government’s plans. Of course every second counts when you are attempting to build a line whose benefits rely entirely on speed, but this figure is so small it could easily be attributed to a miscalculation – and the vital issue of capacity has not been addressed to the same extent.

The Government seems intent on sticking to its plans, just mitigating some of the problems with the existing route to try to appease its opponents, rather than a complete change of route – unless Greening is planning a real new year surprise.