Looks like the noise about Northolt's non compliance with civilian minima and regulations has hit the headlines all over again:
Queen's airfield is not safe for planes, secret MoD files show - Telegraph
and a piece today about possible airline use - but only with significant changes (but nothing the airlines operate will happily use a 1199m LDA runway!):
BTNews: The Business Travel News
and just seen this site where the Mott McDonald report on the airport's non-compliances can be downloaded after a Freedom of Information request unearthed it from the bowels of the MOD - the above mentioned 'secret MOD files'.
www.wikinortholt.com
Clearly, with over 90% civil use, but non-compliance with civil standards, something's going to change. Don't think business aviation will continue to be a user if the runway goes down to say Code 2B standards, just King Airs and the odd M2 or Mustang perhaps!