Messing about on google flights and Flybe come out as an option on most of their routes aside from Leeds - Heathrow. When I put that option in it only shows BA from Manchester?
I'm not sure if google flights is a big driver of bookings but it can't be a bad thing if they fix that to get themselves showing on there. Flybe are about £80-£90 cheaper than the train next week on that city pairing.