Surely in these days of information technology and ACDM, EGCC is aware of the number of a/c which have filed it as an alternate?
Or is that too much to ask.
In the 1990s, it was not uncommon for long-term parked a/c to be re-positioned, to free up stands for impending div-arrivals. I seem to remember 3 in the engine-run bay on several occasions.
Also, if, (as was suggested here before), the airport had invested in multi-storey car parks, (which would also serve the impending 'Airport City' development), it would be able to use the apron for the purpose it was intended for.