My techie amigos tell me that there was a suggestion (from Scotland) that it might be a good idea to cancel the cutover thing that means SWIMM happens. The Swanwick big cheeses thought this not a good idea so it's going ahead.
A source close to a Swanwick supervisor said that the last time this happened 'there was chaos' and this was during winter schedules.
The thought of several 747 loads of beered-up footy fans waiting for slots through Swanwick airspace (if it's actually opening that night) doesn't bear thinking about, does it?