The £10billion HS4Air line would run partly alongside the M25, looping around London and providing the first direct route between the UK’s two busiest airports.
The line would run for a total of 87 miles between Ashford in Kent and Denham, northwest of London.
It would provide a link between HS1, which runs between the Channel Tunnel and London, and the planned HS2 rail line, which will run from the capital to major cities in the north.

HS4Air has been developed by London-based Expedition Engineering with Weston Williamson + Partners and planning and development consultants Turley.
Plans will be submitted to the Department for Transport by the end of the month

"This generates huge regeneration potential and much wider economic benefits for the whole country."
HS4Air will reduce journey times as follows:
Manchester to Heathrow: 1 hour 10 mins (typically 3 hours 20 mins today)
Heathrow to Gatwick: 15 minutes (typically 1 hour 30 mins today)
Cardiff to Heathrow: 1 hour 40 mins (typically 2 hours 50 mins today)
Birmingham to Paris: 3 hours (typically 3 hours 50 minutes by air)
"By allowing London to be bypassed at high speed, economic activity between the UK regions and Europe can expect to grow."