One of my mates is flying Y on BA between LHR and TXL. They have Qantas Club membership and are hoping to use the Terraces Lounge at LHR T1. Are they eligible?

I thought you had to be flying on a BA flight with a QF codeshare flight number to gain access. Or is it the case that they can use the lounge as long as they are flying with BA.

What they are hoping is that based in Europe for six months they can fly around the place on cheapo BA tickets using BA lounges all the time on the back of their Qantas Club membership. If they can do that, it turns out to be a hell of a bargain.