Photo via Twitter/planestupid

U.K. Prime Minister David Cameron could give the OK to expand London’s Heathrow Airport with an additional runway before the end of the year — and opponents are not happy about this fact.

Members of an anti-expansion group dubbed “Plane Stupid” took action at Europe’s busiest airport on Thanksgiving Day, blocking a Heathrow approach tunnel with vehicles, to which they chained themselves, Reuters reported. Signs were draped on the vans, emblazoned with slogans shouting down the proposed third runway.

This isn’t the first time Plane Stupid has disrupted airport operations. In July, dozens of flights were canceled when protesters from the group chained themselves together on the runway.

Supporters say the added runway will enable new flights and give the economy a shot in the arm, according to Reuters, but opponents — which includes locals and climate change organizations — have concerns about increased noise levels and air pollution. 

During the protest, Plane Stupid tweeted the factoid, “if aviation growth isn't reduced, by 2037 aviation alone could emit all of the #carbon it's safe for the UK to emit.”

The group of activists obstructed car and taxi tunnel access to three of the five airport terminals with three vehicles, Reuters said. Police would end up arresting five individuals at the scene.

In a series of tweets, Heathrow advised fliers to allow for extra travel time due to the protest, and provided alternate route information. Once the obstruction was cleared, the airport tweeted,

“We thank all passengers and road users for their patience this morning and apologize for any disruption caused by the protest.”

if aviation growth isn't reduced, by 2037 aviation alone could emit all of the #carbon it's safe for the UK to emit pic.twitter.com/lQaQ8N4UdY

— Plane Stupid (@planestupid) November 26, 2015

At Heathrow now pic.twitter.com/tZ4P5GlqSS

— ian stopher (@ianmstopher) November 26, 2015

We thank all passengers and road users for their patience this morning and apologise for any disruption caused by the protest. 2/2

— Heathrow Airport (@HeathrowAirport) November 26, 2015

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