Originally Posted by guv1976

The fact that BA only flies into LGW from CAG does not preclude connecting to AA or BA out of LHR. You, of course, would be responsible for getting yourself and your luggage from LGW to LHR (just as if you were doing a JFK-LGA connection). But it appears that BA's flight schedule from CAG to LGW would require an overnight in LON -- or perhaps somewhere in the U.S. -- so not ideal, especially if you're looking for something economical.

For a one-seat ride LGW <==> LHR, visit:

https://www.nationalexpress.com/en

Short of routing via LON, I doubt that you will be able to book a protected connection.