Just found this:
It’s important to get your aircraft parking requests in as soon as possible due to limited availability in the London area. While airport slots are an absolute requirement at all London-area airports during the Olympics period, they will not be issued until your aircraft parking has been confirmed. Stansted, London (EGSS), for example, has airport slots for 50 aircraft movements per hour (takeoff and landing combined), but long-term aircraft parking may not always be available, particularly if requested closer to the Olympics. For late requests, you may be able to drop and reposition to an outlying area. Some ground handlers are keeping some stands free (with four hour parking limits) to allow operators to drop and go when parking is unavailable. Options will become fewer and fewer the longer you put off confirming parking and services over the busy summer period.
...and....
Charter (non-scheduled commercial) operators must apply to U.K. Department of Transport (DFT) for a landing permit with lead time of five working days preferred (and minimum of 48 working hours’ notice). Once permits are approved, schedule changes can usually be accommodated. If the requested schedule change exceeds 24 hours of the approved arrival or departure time, a permit revision is required and can usually be accomplished the same day during business hours. Passenger changes (additions or deletions) require resubmission of a charter landing permit request due to cabotage restrictions. Charter (non-scheduled commercial) operators traveling to London must provide evidence to the U.K. DFT that they have confirmed airport slots and aircraft parking for the Olympics along with all the other required documentation for the landing permit.
All standard stuff but good to keep in mind.
CP