If MAPLC are really keen to exact revenge on BA/BMI then surely the best way for them to do this would be to offer well-timed slots at a discounted price to the likes of Cathay, United, Delta et al to that pax are no longer relying upon BA and BMI for longhauls through Heathrow. Ensure that facitities are up to standard and keep the prices for airlines to operate out of MAN competative in the long-term.
Steve