Originally Posted by
number_6
Absolutely no access. Upon arrival you are segregated -- must go landside, unless you have onward boarding passes. Without a connecting flight, security will not let you through to reach the lounge. If you do manage to talk your way past security somehow, the ultra diligent BA lounge dragons will not let you in. Arrival lounges are not an Emerald benefit. If you had flown AA into LHR, where AA has an arrivals lounge land-side, you would still be denined free access (paid access is available for GBP50 for the 2 of you, much like an AC day pass); but AA has no such lounge at LGW.
Fundamentally this is correct, but with one small error. The OP states that he is not connecting at LGW & so will be going landside. However, the arrivals lounge
is landside, in an hotel. (Most arrivals lounges are landside, certainly BA at LGW, JNB, & LHR T1/T4, as well as AF at CDG. This is because most users will be terminatiing their journey & have no airside access.)
Unfortunately for the OP, "Arrival lounges are not an Emerald benefit". (The QF exception to this is a result of the BA/QF sharing agreement for UK<>Oz.)