I'm travelling HEL-LHR-NCL at the end of February. After several schedule changes to the HEL-LHR leg, BA have now removed my return journey from MMB without saying anything to me. When I enquired, I was told that it's because the connection time from T3 to T5 is too short. The Heathrow website doesn't seem to think that 90 minutes to connect using the terminal buses should be a problem.

Has anyone done this before? Is it possible?

They want to put me onto a Finnair flight earlier in the day, but I'd lose valuable hours in Helsinki if this were to be the case. I dread to think what might have happened if I hadn't enquired - would I have been stranded?!