What do you mean "BHX fights its corner"? What does BHX gain by stopping LHR expand? Seriously, because American Airlines just walked away from there for the second time. Perhaps they were making too much money? What's the real world gain?
MPs won't be "unaware" as it will come up in a heated debate and a decision will be made afterwards. The local region will benefit from an expanded LHR, an expanded BHX clearly has no traction in some markets.