A BAA spokesperson said:
"BAA believes this country needs both a third runway at Heathrow and high speed rail. To prioritise one over the other is a false choice and will put Britain's future competitiveness at risk.
It is not clear how this proposal will resolve the lack of airport capacity, a problem which must urgently be addressed.
The total number of flights to Manchester and Leeds/Bradford is only 13,356 or less than 3% of Heathrow's total flights.
Even if every flight from Manchester and Leeds/Bradford were replaced by a new high speed rail line then Heathrow would still be operating at 97% of capacity.
There are currently no flights from Birmingham to Heathrow."