It says that such excessive speeds require straighter tracks which prevent new tracks following valleys, existing rail lines or motorways.
This means that only routes that cut through open countryside are being considered in areas such as Warwickshire and Staffordshire.
CPRE West Midlands policy campaigner Gerald Kells said: "Ministers’ attempts to boast about having the fastest rail line in the world come at huge cost to the tranquillity and beauty of the countryside in the West Midlands.
"The controversy these proposals are generating could derail the government’s welcome vision to make rail the long distance travel mode of choice."
The organisation is asking for the public consultation proposed for 2011 to include real choices, including a 186mph route like the Channel Tunnel Rail Link that runs along existing motorways and railways, keeping intrusion into the countryside to a minimum.