Hillingdon Council dropped off some leaflets in the office yesterday with information for local residents and businesses.
Included in the information is expected "mass action" from mid-day on Sunday 19 to mid-day on monday 20 with up to 1500 people involved.
"This is likely to include protests and direct action and therefore it is possible that there may be some disruption to transport services and road routes around the airport during that time."
I have also heard rumours of them moving toward the perimeter fence during that time.