Improved links between HS1 and HS2 railways could reduce air travel

A report by a high-speed rail lobby group is calling for improved links between HS1 and HS2 in London to encourage more people to switch from planes to trains.
The High Speed Rail Group (HSRG) looked at rail travel in the UK as a whole and into the European mainland to see what routes could encourage fewer flights and more train trips.
The rationale put forward is the environmental impact of rail vs planes, which has been fairly clear for some time. Data from the European Environmental Agency (E