EGCC my expererience of Manchester is it can hardly cope on a good day,its potential for taking many diversions is extremely limited by ground handling constraints.I remember diverting there from LGW many years ago and having to wait 3 hours to get my bags and pax offloaded.Should this situation arise I would suggest the government cancel all internal flights and provide military fire cover (by legal dispensation if necessary) from military airfields.LHR , LGW and GLA need to be kept open as national arteries I would suggest the remaining BAA airports could be allowed to close. Hopefuly the plod can provide security cover at those airports deemed necessary to remain open in the national interest.