Manchester and Birmingham would be the most probable airports that could have a connecting flight.
Leeds is roughtly halfway between Edinburgh and London.
Leeds in Yorkshire approx.
where is halfway between newcastle and london
The closest Junction to exactly half way is the A684 on the Route recomended By our Friends at Google Maps I dont know if there are any services though, I have never gotten off the Motorway there.
The first postal service between Edinburgh and London was thought to be about the 50s around about the50s anway
Salisbury, England is near the halfway mark between London and Devon, England.
The flight distance from Edinburgh Airport to London Heathrow Airport is 332 miles / 534 km
London is south of Edinburgh. London is in England. Edinburgh is in Scotland.
The distance directly from London to Edinburgh is approximately 332 miles (535 km).330.42 miles (531.76 kilometers)
Istanbul
About 7 hours
332 MI/ 534 Km