Video of the protest posted was on social media by Ian Stopher
Three members of the Plane Stupid campaign group parked a van across the lanes of the access tunnel into the airport and then locked themselves to it.
Heathrow airport management said in a statement “we can confirm there is a protest taking place in the inbound tunnel, which is currently affecting traffic around the central terminal area and Terminals 2 and 3…
“Police are now on site but we urge passengers to allow extra time getting to the airport today.”
Plane Stupid posted an image of the protest on their Twitter feed, featuring a banner saying “No ifs, no buts, no third runway” – echoing a promise made by David Cameron during the election campaign in 2009.