Extinction Rebellion protesters will take their fight to save the planet to Civic Hall as they join residents opposed to a Leeds Bradford Airport (LBA) expansion.
A group of five residents will form a deputation to Leeds City Council over the plans at its full meeting on Wednesday September 11.
Extinction Rebellion will has announced that it will join them in support, and it asking all those who oppose the expansion to join them in peaceful protest at the Civic Hall.
Members described the council as an "enthusiastic backer" of the plan.
An application to build a multi-million pound, three-storey extension to LBA's terminal building was approved in December last year.
Holt Park resident Dru Long, who is set to lead the deputation, said: "In a world seeking to prevent climate breakdown, there is no place for more flying, and Leeds simply
cannot meet its carbon reduction targets if the planned expansion of the airport goes ahead.
"It's time for the council to show that it is serious about the climate emergency that we face."
The council declared a climate emergency in March, committing to sign up to a "science-based carbon reduction target", but Extinction Rebellion claim there are "great inconsistencies between the words and the actions".
Its multiple-day protest in July caused widespread traffic disruption in Leeds and cost West Yorkshire Police £197,928 to handle.
Campaigners in Sheffield will block roads during another course of action on Monday September 9.
The council has been approached for comment.